Asparagus and amaranth soup #wisegreenwitch

I’m finding that writing a cookbook is rather more tricky than you might think. Especially an environmentally friendly recipe book, which means presenting low-cost, seasonal, locavore dishes with a strong emphasis on vegetarian and vegan offerings. At the same time, I refuse to accept that Worthy Food has to be Dull Food (remembering all those lentil stews served in the stern lefty communes of my youth — eek).

So my publisher and I thought up the following guidelines or rules for inclusion: everything has to be (1) delicious; (2) fairly easy to make; (3) nourishing; and (4) inexpensive, with easily available ingredients.

This makes for an interesting challenge, especially as the book is geared towards novice cooks — often young people who would like to eat in ways that lessen their impact on the planet, but who don't have that much knowledge of either cooking or nutrition, and don't own posh kitchen equipment, or have money to throw around.

That said, why on earth am I posting a recipe for asparagus and amaranth soup, of all esoteric things? This is because of the great rule of green cooking (alluded to in my earlier posts on water and waste): cook with what you have. What’s in the fridge, the pantry, the veg garden, or cheap in the shops because it's seasonal.

The other principle this soup demonstrates is that everyone needs to learn just a few basic cooking skills. These are often fascinating little experiments in food science or chemistry, and you need to know both the principles and the techniques. A lot of cooking is very easy because it simply involves combining things (as in most salads, although the dressings get a bit more interesting, because they usually involve the chemical process known as emulsion). But there are still a few things you need to master if you're going to make tasty basic dishes.

So back to my soup. Which arose because my local Food Lovers' Market (which I frequent because much of their produce is sold loose, and the rest isn't too hideously overpackaged) was selling hefty bunches of fat fresh asparagus, four for fifty bucks. I adore fresh asparagus, usually a luxury, so that was a no-brainer. Went home, steamed the lot and ate asparagus hot with butter and cold with aioli for the next two days. But I still had a lot of steamed asparagus to use up...

My friend Gail had just been to Uganda, and being a sensible person with an excellent understanding of what is truly important in life, she offered to bring back FOOD for her friends. I begged for tea masala and amaranth flour. I first encountered amaranth in the Caribbean over ten years ago; it’s a wonder food (basically a semi-tropical weed) and you can read more about it here. I found it added to the West Indian dish broadly known as “provisions”, a mix of yams, taro, cassava, to which greens and salt fish might be added. This arose when colonial settlers put slaves and indentured labourers to the backbreaking work of growing sugar cane and other crops in a sweltering climate, while feeding them as cheaply as possible, and I could write an entire post about the health benefits — ironic given its brutal history — and Caribbean food in general (including the story of how Elinor Sisulu and I ended up in a beautiful book on the food of Barbados), but let me gallop down that avenue another day.

My interest in amaranth flour was whether I could use it as a substitute for wheat flour in making a white sauce — the starting point for many creamy or thick soups. A soup that starts with a white sauce is velvety and well suited to ingredients with more delicate flavours. And making a white sauce is one of those things (see above) every cook needs to know how to do.

Here goes (vegetarian version first): melt two heaped tablespoons of butter in a pot on medium heat. When the butter is a slightly sizzling puddle, sprinkle in two heaped tablespoons of flour and stir like hell with a wooden spoon (yes, it has to be a wooden spoon — the only acceptable substitutes are those indestructible silicon spatulas, but stick with a wooden spoon for now). The fat and flour will combine to form a kind of patty. Push the patty around the pot for a minute or two so that the flour cooks — otherwise your sauce will taste raw. The patty shouldn’t go brown, but it should start to sizzle very slightly around the edges. Have a cup (250 ml) of milk/vegetable stock on standby (baker Hazel Carmichael taught me that if this liquid is room temperature or very slightly heated, the sauce is a lot easier to make). Now start adding this liquid to the pot slowly while beating madly with your wooden spoon. At first it will look as if you are mixing cement, then a lumpy liquid will emerge. Your goal is to bash all the lumps out. Stir energetically, and miraculously the whole thing will turn into a smooth creamy sauce. If there are still lumps (the story of my life), grab a whisk and beat the mixture like crazy. After a few minutes, the sauce will start to thicken. Congratulations, you’ve just made white sauce. For soup, add another cup of liquid and repeat all the mad stirring.

Why the amaranth flour? Some people choose to avoid gluten — the protein found in wheat, barley and rye grains — or it makes them really ill. I once had a strapping sporty housemate with coeliac disease, and a gram of wheat flour could land him in hospital. So I am always on the lookout for substitutes. Besides, for reliable thickening and smoothness — the two things you want in a white sauce — many find that using Maizena (corn flour) instead of wheat flour works a charm, and I wanted to see how amaranth compared. In this case, the slight vegetable taste of the greenish amaranth flour went very nicely with the asparagus, and made for a very silky sauce.

Once you have a fairly thin and runny sauce, you can now add any of the following veggies: steamed broccoli or cauliflower or both; steamed fresh asparagus; spinach or chard (no need to precook, just chop finely and chuck in); baby marrows (either steamed or finely chopped, raw), salt and other seasonings (this depends a lot on the liquid you use, of which more soon). You can do so much at this point; if your white sauce is thick and not too runny and you add spinach and let it cook on low heat for a few minutes, bam, you have creamed spinach, a vegetarian standby that’s great on its own, and even better poured over butternut or chicken. If you’re set on soup, make the sauce thinner and runnier, and if you’re using baby marrows or broccoli, you could add half a cup full of feta or grated parmesan cheese just before blending and serving. A thumb-sized bit of blue cheese is particularly good in baby marrow soup. Note that veggies like spinach and baby marrows ooze water, so check your sauce isn't too runny before you add them — it will thin out a little as they cook. Ideally, you should buzz these soups with a stick blender for super-smooth results, but it’s not a trainsmash if you don’t.

For vegans: substitute the butter with coconut oil (or another vegetable oil). You can also use vegan stock (and here I reveal the secret of my gourmet home-made vegan stock) or the drained liquid from a tin of chickpeas (in which case you won't need to add salt) instead of milk. Keep the chickpeas for making your own hummus, or use them as the basis for a salad or curry.

Making a white sauce takes a little bit of practice, but it's an NB part of being an adult. Srsly. Like learning how to change a tyre or an electrical plug. Make sure your children (of ALL genders) know how to do this. If you have seasonal veggies, a little flour, fat and liquid, it means that a comforting soup is never far away. And as you can see, you can make these dishes for vegetarians, vegans, gluten-intolerant folk and more.

You can serve this soup hot or cold. I had a bowl the next day, cold, with double-cream yoghurt swirled in and a grinding of multi-coloured peppercorns.