Eat To Live

Garlic and onion skins full of goodness

Add them into soups or steep them in boiling water

A street vendor sells bulbs of garlic. PHOTO: REUTERS

Don't throw away those skins.

I've heard about not peeling carrots, apples and pears before eating them, as much of the nutrients lie in the skin, but onions and garlic?

Well, research now shows that just like fruit and vegetables, a lot of the nutrients is found in the skins of onions and garlic.

It's great especially for a lazy cook like me. No need to peel them before using!

  • BLACK BEAN SOUP WITH ONION SKIN

  • INGREDIENTS

    2 cups dried black beans, rinsed, soaked overnight and drained

    2 bay leaves

    5 cups onion skin water, made from soaking onion skins in boiling water, then strained

    2 tbs olive oil

    2 large onions, chopped fine, skins reserved

    4 garlic cloves, chopped

    1 carrot, chopped

    1 celery rib, chopped

    1½ tsps salt, or to taste

    1 tbs ground cumin

    1 tsp chilli flakes

    2 cups chicken stock (either store-bought or homemade)

    1 red bell pepper, roughly chopped

    Fresh coriander, chopped

    Low-fat yogurt

    METHOD

    Place the beans in a pot. Add five cups of onion water and bay leaves.

    Bring to a boil, then reduce to a simmer.

    Cover and cook for about an hour until the beans are tender. Remove the bay leaves.

    Meanwhile, heat the olive oil in a second pot, a large one, until the oil is hot but not smoking. Add chopped onion, garlic, celery and carrot.

    Cook, stirring occasionally until lightly browned and softened.

    Season with salt.

    Lower the heat and stir in cumin powder and chilli flakes.

    Once the beans are tender, add the beans, their cooking liquid and chicken stock to the second pot.

    Bring to a boil, add the chopped red pepper, then reduce the heat to a simmer.

    Cook, stirring occasionally, for about half an hour. Taste and adjust the seasoning if needed.

    The soup will thicken; if it gets too thick, add some water and adjust the seasoning again.

    Serve, garnished with fresh coriander and yogurt.

    SERVES 6-8

Dr Marilyn Glenville, an expert in nutritional therapy in both Britain and the United States, was reported as saying in the London Daily Mail newspaper that peeling garlic cloves removes the phenylpropanoid antioxidants which help fight the ageing process and protect the heart.

Another well-known advocate of alternative medicine, Dr Mehmet Cengiz Oz, better known as Dr Oz, author and television personality, also advocates not peeling the onion.

While onions are a good source of antioxidants, the skin actually has more antioxidants than the onion itself. It is also rich in quercetin - a flavonol that can reduce blood pressure and prevent arterial plaque that can cause stroke, he said.

But not any old onion should be used for such treatment.

Despite the controversy over the efficacy of eating organic, I would use only organic onions, otherwise you may be inadvertently introducing pesticides into your diet.

And if you are worried about chewing into the papery skins of onions, steep them first.

Whether cooking a soup or a stew, you can throw in the skins and let them stew.

You can then take the skins out midway, as most of the nutrients would have steeped into the liquid, or you can eat them.

Or you can make a tea of them, steeping the skins in boiling water, then straining them to use the liquid, which I did here for a black bean soup.

If you use red-skinned onions, you will get a lovely rose-coloured liquid for the pot.

While the Chinese do cook black beans, a fibre- and protein-filled food that is rich with anthocyanins, which are plant pigments that may help lower the risks of diabetes, heart disease and cancer, they do it in a simple soup made with pig's tail.

Here, it is a chunky, hearty soup, cooked often with a ham bone or bacon.

It is a filling and comforting soup, perfect for those days when you do not feel like doing much in the kitchen, for it sort of cooks itself.

I cook it when I want only soup for dinner, but I omit the ham bone as I find the smokey flavour too overpowering.

Instead, I rely on chicken stock to provide fullness to the broth.

Besides, the beans themselves deliver lots of big flavours to the pot, together with a red bell pepper, a celery stick, a carrot and, yes, those onions.

Aside from the bay leaf, I love adding chilli flakes and a dollop of sour cream or yogurt to cut through the richness.

Redolent with spicy flavours and chockful with nutritional goodness, it is a meal in a cup.

  • Sylvia Tan is a freelance writer and cookbook author. Her previous Eat To Live recipes can be found in two cookbooks, Eat To Live and Taste.

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A version of this article appeared in the print edition of The Straits Times on September 29, 2015, with the headline Garlic and onion skins full of goodness. Subscribe