Soup has a reputation as the thing you make when there is nothing to make. That reputation comes from soup built on water. Build it on something with flavour and the same vegetables taste like a decision rather than an accident.
Stock, without the ceremony
Stock is water that has spent time with bones, vegetables or both. It does not need a recipe. It needs three habits.
Keep a bag in the freezer. Onion tops and skins, leek greens, carrot ends, celery bases, herb stalks, mushroom stems, parmesan rinds. Roast chicken carcasses in a separate bag. When a bag is full, it is stock day.
Leave some things out. Cabbage, broccoli and sprouts turn stock sulphurous. Potato peel makes it cloudy. Beetroot makes everything pink. Anything actually spoiled makes it bad, not rustic.
Never let it boil. A hard boil emulsifies fat into the liquid and drags scum through it, which is why cloudy stock tastes muddy. You want the surface barely moving for an hour with vegetables, two to four hours with bones.
Roast first if you want depth
Raw bones and vegetables give a pale, clean stock: good for delicate soups. Roasted bones and vegetables give a browner, rounder one. Twenty minutes at 220°C before the pot is the difference between chicken soup and proper chicken soup.
Add a splash of water to the roasting tray afterwards and scrape it into the pot. That is where a lot of the flavour is sitting.
Salt at the end, not at the start
Stock reduces while it simmers. Salt it early and you may end up with something too salty to use in anything else. Season the finished dish, not the base.
Turning stock into soup
Four steps, in this order, cover most soups.
- Sweat the aromatics. Onion, and usually carrot and celery, in fat over low heat until soft and sweet, not brown. This takes ten minutes and is the step people rush.
- Bloom the flavour. Garlic, spices, tomato purée, a spoon of miso or doenjang: thirty seconds in the fat wakes them up.
- Add the main thing and the liquid. Vegetables, pulses, grains, whatever the soup is. Then just enough stock to cover; you can loosen later, you cannot easily thicken.
- Finish sharp. Lemon, vinegar, yoghurt, herbs, chilli oil. This is what stops soup tasting flat.
Texture is a choice
Blending everything gives a smooth, restaurant-ish result. Blending half and stirring it back gives body while leaving something to chew. Leaving it entirely chunky makes it a stew that needs bread. None of these is more correct, but a soup that is accidentally between two of them tastes unfinished.
Starch does the thickening. A potato, a handful of rice or a tin of beans blended in will thicken a soup far better than flour, and taste of something while doing it.
Freezing
Stock freezes for months. Freeze it in the amounts you actually cook with, not one enormous block. Soup freezes well too, with two exceptions: anything with pasta in it turns to paste, and dairy can split on reheating. Freeze the base, add the pasta or the cream when you serve it.
The shortcut, honestly
A good stock cube is not a crime. It is salt with flavour, so use less salt elsewhere and add something of your own: a parmesan rind, a dried mushroom, a strip of kombu, the roasting juices from Sunday. Ten minutes of simmering with real ingredients moves a cube a surprising distance.