Superfoods: Easy lentil soup

Lentil soup gets a bad reputation, and most of it is deserved by the bad versions. The watery kind where the lentils dissolve into nothing, or the aggressively health-food version that tastes like it's punishing you. The thing is, lentil soup is actually really good when you treat it like a proper vegetable braise instead of just boiling legumes in water.

This is the version I make. Black lentils, the standard soup vegetables, canned tomatoes, stock. The soaking step is non-negotiable and it makes a bigger difference than you'd expect. It's also one of the cheapest pantry meals going: lentils cost almost nothing and the rest is usually already in the cupboard.

A quick note on lentil types

Two types you'll find in any supermarket. Red lentils: no soaking needed, cook in 30 minutes, turn to mush. Great for smooth Indian-style dals. Black lentils: need 1.5 to 2 hours of soaking, cook in about an hour, hold their shape. That's what we're doing here. The texture is much better for soup -- you get actual lentils in the bowl, not porridge.

Ingredients (serves 2)

• 200g black lentils, soaked for 2 hours and drained
• Half an onion, chopped
• 2 carrots, chopped
• 1 celery stick, chopped
• Half a can of peeled tomatoes (about 200g)
• 1 litre of liquid (stock, water, or a mix -- more on this below)
• Olive oil, salt, and pepper
• 1 tablespoon red wine vinegar (optional but recommended)

How to make it

Soak the lentils in cold water for 2 hours before you start. Set a timer and forget about them.

When the 2 hours are almost up, get a large pot over medium-high heat and add a generous glug of olive oil. Add the onion and cook until it's soft and translucent, about 5 minutes.

Add the carrots and celery. Stir them around to coat in the oil and let them cook for a minute.

Drain the lentils and add them to the pot. Add the tomatoes and break them up with a wooden spoon. Stir everything together, then pour in the liquid.

Bring to a boil, then drop the heat to medium-low. Cover the pot and let it simmer for about an hour. The lentils should be tender but still holding their shape. Taste for salt and pepper -- you'll likely need more than you think.

If you have it, stir in a tablespoon of red wine vinegar right at the end. It cuts through the earthiness and brings the whole thing together. I always add it.

On the liquid, the lentils, and the vinegar

On the liquid: Stock gives you more depth than water, but water alone works fine. I usually do half vegetable stock, half water. Full stock can make it a bit heavy. Avoid chicken stock here -- the flavour fights the lentils in a way that vegetable stock doesn't.

On the soaking: Don't skip it. The difference between soaked and unsoaked black lentils is about 30 minutes of extra cooking time and the texture never quite recovers from being rushed. If you forget to soak them in advance, use red lentils instead and cut the simmer time to 30 minutes.

On the vinegar: It sounds like a strange addition but it works. Red wine vinegar, apple cider vinegar, or a squeeze of lemon all do the same job. It just lifts everything at the end. Try it once and you'll keep doing it.

On storage: This soup keeps well in the fridge for 3 days and improves slightly the next day once the lentils have absorbed more of the liquid. Add a splash of water when reheating.