The nutritional benefit of root-to-stem cooking
We take a look at the social and health benefits of root-to-stem cooking, or using the whole plant — root, leaves, skin, stems and flowers — when you’re cooking up a storm in the kitchen.
There’s been a lot of talk about the concept of nose-to-tail cooking when it comes to cooking meat, but what about our forgotten plants? Although it’s not a new concept, root-to-stem cooking is gaining traction, not only in Australian restaurants but also in households by people keen to cook more consciously and reduce their food waste. Most modern recipe books encourage cooks to cut, deseed and peel vegetables and fruits, so it’s no surprise that a staggering amount of edible and nutritious produce ends up in the trash. According to OzHarvest, 35 per cent of the average household bin is attributed to food waste, with more than 5 million tonnes of food ending up as landfill in Australia (enough to fill 9000 Olympic-sized swimming pools!).
So, what exactly does it mean to cook root-to-stem? Root-to-stem cooking sees the whole food item being used in the kitchen, from the zest of your lemons to the green tops of carrots. This includes the leaves, skins, seeds, stalks and everything in between. Cooking root-to-stem may not come easily at first, but with careful meal planning you can reap the rewards and save your household money while you’re at it.
By cooking more consciously, you will stop throwing away useful food scraps and rethink the way you cook by getting a bit creative in the kitchen. Here are some ways to get the most out of your food to ensure nothing is wasted and all the produce ends up on your dinner plate instead of in the rubbish bin.
Think beyond composting and cook whole
Composting is great, but there are plenty of ways to use up your food scraps before they hit your compost heap. Cooking consciously with the whole of the food can definitely reduce the amount of food that goes to waste and is the simplest way to adopt root-to-stem cooking for beginners. In many cases, the parts of the produce which are often thrown out contain more nutrition than the commonly edible parts and are packed full of antioxidants and dietary fibre, also known as NSP (non-starch polysaccharides) like hemicellulose, pectin and more. The leaves, stems, stalks and skins of vegetables have their own unique tastes and textures so it’s like getting multiple veggies in one package and you have the added benefit of maximising your nutrient intake while you’re at it.
Sweet potatoes, carrots and potatoes are the perfect vegetable to roast whole, without the need to peel off their skins. Simply scrub them clean and they are ready to be cooked. Roast a jacket potato in the oven for an easy mid-week dinner and fill it with your toppings of choice or make a delicious soup using whole carrots and sweet potatoes; just blanch the carrot tops lightly first and blitz them with your favourite vegetables or simply use as a garnish. Cauliflowers are also a great vegetable to cook whole. Make some cauliflower rice by finely dicing the whole cauliflower or cut the cauliflower into “steaks” and roast them in the oven. They will literally melt in your mouth if you cook them for long enough.
Make vegetable stock or soup
One of the easiest ways to use up all your leftover food scraps is to convert them into a delicious homemade vegetable stock. A great way to do this is to build up a vegetable scrap heap in an airtight freezer container that holds both scraps and any vegetables past their prime. When the container is full, make a big batch of vegetable stock. Carrot tops, leeks, cabbage cores and broccoli stalks are all a great base for a beautiful stock as well as onions and garlic (in their skins), but you can use pretty much everything. Just be wary with beetroot, unless you want a very discoloured pink stock at the end of it! Simply add vegetables, water, herbs and simmer in a saucepan for about an hour and then strain accordingly.
Making soup is also another great way to use up leftover vegetables and sneak in extra ingredients or things you need to use up in the freezer. Don’t forget your ugly vegetables! They might not be attractive enough as a garnish or salad, but they’re perfect blitzed up in a soup — you won’t even notice the difference.
Don’t toss the leaves
Don’t toss the leaves from your beetroot, cauliflower, turnip greens and radish tops. Vegetable greens and leaves are packed full of flavour, nutrient-dense and rich in macro and micronutrients, which are all essential for a balanced diet. For example, broccoli leaves are higher in vitamins than the actual broccoli florets, particularly vitamin A. Similarly, beetroot greens are a great source of calcium, magnesium and iron and have a deep earthy flavour profile. Did you know that the whole beetroot plant can be eaten both cooked and raw including the stem, leaves and the actual bulb?
Try making a pesto with your leftover greens by blitzing them all up in a food processor with garlic, herbs, salt, pepper and oil. Greens and leaves are also great to cook in a stir-fry or salad by simply sautéing them with some olive oil and garlic. Some greens, particularly carrot tops, have the tendency to be bitter but blanching them takes most of the bitterness away. To blanch the greens, bring a large saucepan of water to the boil and briefly drop the greens in for a very short period of time then transfer the greens to an ice bath or very cold water to stop the cooking process.
Spice up your cooking
Are you a culprit of cutting off and discarding the stems and stalks of herbs and vegetables when you cook? Next time you’re cooking, don’t throw out your herb stems. It’s easy to forget they are also part of the edible part so make sure you don’t leave them behind. Herbs are also great in salads, soups and stews and can really lift a dish. The stems of herbs like dill, basil, coriander and parsley are full of flavour and nutrients. Herbs that have woodier stems like rosemary and tough asparagus stalks are more suitable for soups and stews.
Broccoli stalks are one of the biggest victims of food waste and more often than not end up in the bin. Chop up the cauliflower and broccoli stalks as well as the florets to really complement your cooking.
Rethink your peels, skins and rinds
Do you have a recipe that calls for just the juice of one lemon? If so, don’t throw out the peel. The skins and peels of fruit and vegetables are a concentrated source of phytochemicals, soluble fibres and antioxidants. For example, apple is particularly rich in quercetin and is found mostly in the peel.
The zest of thick-skinned citrus fruits like lemons, limes and oranges are great in cakes or bakes, or if you’re feeling extra creative try candying them or drying them to infuse in a pot of tea. Another great way to use leftover fruit peels is to whip them into a smoothie or juice. Even though most people can’t stand the thought of eating furry kiwi peels and banana peels, they are completely inoffensive in a smoothie.
Vegetable peels are also one of the most underutilised ingredients. Potato skins are loaded with vitamin C and B6, potassium, manganese and copper. If you can’t bear the thought of an unpeeled potato, roast the peels in the oven to make fries or fritters with some simple seasoning and a drizzle of olive oil. So, next time you make mashed or boiled potatoes, just scrub the potatoes really well and leave the peels on.
Make your own sauces and condiments
Making homemade sauces, dressings and condiments is easier than you may think — you just need to get a bit creative with your leftovers. Fresh herbs including their leaves and stems can be blitzed up in no time to make a delicious sauce or dressing.
Seeds from winter squash and pumpkin, just to name a few, can be roasted and added to salads for extra texture and crunch. They are also rich in nutrients like fibre and magnesium. A great way to use seeds is to roast them in the oven lightly with subtle spices like cumin and paprika. On the fruit side, papaya and jackfruit seeds are also packed full of health benefits and are great sprinkled on your morning muesli or as an afternoon snack.
Dehydrate or pickle your food scraps
Pickled and dehydrated vegetables and fruit are definitely making a popular comeback. The pickling process tenderises and adds flavour to tough scraps like cabbage stems, kale and chard ribs and even watermelon rind.
Meanwhile, the roots and skins of most produce, including beetroot and carrots, can easily be dehydrated and used as crisps or ribbons.
Who else loves a stir-fry for a simple mid-week dinner? The best thing about stir-fries is they have no rules, so they are a perfect way to use up all your leftovers and your vegetable scrap heap in the freezer. Chop up your vegetables and all of their accompanying roots and stalks as the perfect base for a stir-fry. Radish tops are also great in a stir-fry, since their leaves are so peppery and pungent.
Root-to-stem cooking can be applied to pretty much any produce under the sun. Just be wary of rhubarb leaves, green potato skins and the seeds of some fruits like apricots since they are mildly poisonous. Root-to-stem cooking is easier than you think and is a great way to keep your kitchen sustainable and ensure you are getting the most out of your produce each week.
Sweet Potato & Carrot Soup
This sweet potato and carrot soup is loaded with vitamins and minerals. Roast the sweet potatoes and carrots in their peels to maximise their nutrient intake. The carrot tops can be used in either the soup or as a garnish on top.
- 500g sweet potatoes (peel on), diced
- 300g carrots, (peel on), sliced
- Green carrot tops, blanched
- 3 tbsp olive oil
- Salt & pepper, to season
- 2 onions, finely chopped
- 3 garlic cloves, finely diced
- 1L vegetable stock
- 2 tbsp red curry paste
- 150g crème fraiche
- Pumpkin seeds
- Greek yoghurt
- White sesame seeds
- Red chilli, seeds on, sliced
- Fresh herbs
- Lime, sliced
- Preheat oven to 200°C. Place sweet potatoes and carrots (with peels on) on a baking tray and drizzle with half the olive oil, season well and roast in the oven for 30 mins.
- While the vegetables are roasting, heat the rest of the olive oil in a large pot. Fry the onions for 5–7 mins until softened and translucent then add the garlic and cook for another minute until aromatic. Add the vegetable stock, red curry paste and leftover onion and garlic peels and simmer for 10 mins. Strain the remaining onion and garlic peels.
- Transfer cooked vegetables to the pot and use a hand mixer to mix until smooth.
- Heat again if required and stir in crème fraiche.
- Serve immediately and top with pumpkin seeds, yoghurt, fresh herbs, lime and garnishes of your choice.
Baked Carrots with Herby Yoghurt
This recipe is super easy to make and is the perfect side dish. Either cook the carrots with the green tops or process them in a food processor with the herbs. Make sure to blanch them slightly first so they aren’t bitter. The herby yoghurt is a great way of using up any leftover herbs (including their stems) in your fridge or freezer.
- 1 bunch baby carrots
- Handful fresh herbs (including stems) such as parsley, dill and basil
- ½ cup Greek yoghurt
- 2 tbsp flaked almonds
- 1 tbsp pumpkin or pepita seeds
- Preheat oven to 200°C. Place baby carrots on a baking tray and drizzle with oil. Bake in oven for 30 mins until just tender.
- While the carrots are baking, blitz up the herbs in a food processor (including carrot tops if desired) and blend with Greek yoghurt in a small bowl.
- Top carrots with herby yoghurt, flaked almonds and toasted pumpkin or pepita seeds.
Stuffed Sweet Jacket Potatoes
These sweet jacket potatoes are perfect cooked whole with the peel on. I have filled these ones with lentils, creamy feta, yoghurt and fresh herbs (I love using parsley and dill) but they can be topped with pretty much anything.
- 2 sweet potatoes, (peel on)
- 2 tbsp olive oil
- Salt & pepper, to season
- 200g cooked lentils
- 100g feta cheese
- 4 tbsp Greek yoghurt
- Bunch fresh herbs, stems on, sliced
- 2 tbsp pine nuts
- Green chilli, sliced (optional)
- Preheat oven to 200°C. Using a fork, prick the sweet potatoes all over and place them on a baking tray and drizzle with olive oil.
- Season well with salt and pepper. Roast for 45–50 mins until tender.
- Remove from the oven and cut in half and fill with lentils and feta cheese. Top with fresh herbs, pine nuts and chilli (if desired).