Hearty Green Lentil and Potato Soup with Spinach

Lentils are one of the oldest cultivated foods we know of. People were growing them in the Fertile Crescent thousands of years ago, and they still turn up in everyday cooking across the Middle East, India, Turkey and the Mediterranean. This soup sits comfortably in that tradition: a pot of humble pulses, a few potatoes for body, and a big handful of spinach for colour and a gentle mineral note. It is the sort of thing you make on a grey afternoon and then forget about until the second day, when it tastes even better.

The green lentils are the reason this soup holds its shape. Unlike red lentils, which break down into a smooth mush, green ones keep their identity, so you get little pockets of firm texture among the softer potato. Cooking them on their own first, as the method does, means you control their tenderness before they meet the stock. I like to check a spoonful after the first twenty minutes; if they still have a bite, the hour of simmering with the potatoes will finish them nicely.

Puréeing only a quarter of the soup is a small trick worth copying. Blend it, then stir it back in, and the broth turns creamy without any cream. Do it in a jug blender if you have one, and be careful with the hot liquid. A stick blender works just as well if you prefer to stay at the pot.

Lemon juice goes in right at the end, and it matters. Heat dulls the bright notes, so a splash stirred in just before the bowl goes out wakes the whole thing up and lets the spinach taste fresh rather than flat. Taste first, then decide how much you want.

This soup keeps well. Cool it quickly, refrigerate it in a sealed container for up to three or four days, and loosen it with a little water or stock when reheating, since the potatoes thicken it as it sits. It also freezes, though the potato can go a little grainy, so I tend to freeze portions without the lemon and add it fresh after reheating.

For serving, a wedge of crusty wholegrain bread is the obvious partner, and a simple green salad with a sharp vinaigrette cuts the earthiness nicely. If you want something more filling, a bowl of plain yoghurt on the side, spooned in at the table, adds tang and softness. A warm spinach and artichoke dip is a fun thing to put out next to it for guests, though I would keep the soup as the main event.

If you want to round out the table, these fit alongside it: Hearty Tomato and Red Lentil Soup makes a good companion if you want a second pot of lentils with a different colour. Roasted Butternut Squash Salad with Mint Yoghurt brings sweetness and contrast to a lunch plate. And Chickpea and Lentil Soup with Sourdough is worth a look if you like the idea of bread baked for dipping.