There is a low wall behind the bar that plays loud music at Piramide Metro station. It is a shady wall, too, and removed from the traffic, so, if you like Cher remixes, it’s a good place to rest or to eat a sandwich. The other day, I passed by and an old man had spread waxed paper on top of the wall and, working with a miniature pen knife, was slicing from a whole melon, discarding the skin and seeds as he went into a bowl near his trolley, and then draping each orange moon with a slice of prosciutto. It crossed my mind to stop and say something before catching my train, about his skill and how good it looked, spread out there like a picture. Someone else, a young man, actually did say something: ‘e un buon matrimono’ – it’s a good marriage (the melon and the prosciutto) – and the melon-cutter agreed. The idea of happy marriages in food stuck in my head, which is far from an original idea, but a good and helpful one for passing time on a train. What is it about the marriage of melon and prosciutto? Contrast, baby! The cool, sweet smoothness of the melon, the dry, salty tear of the pork. And they are a couple who fit anywhere, be that a fancy table or a low wall. One marriage leads to another: melon and prosciutto, prosciutto and figs, figs and white pizza , white pizza and sausages, sausages and lentils, lentils and tomato … a lentil-and-tomato soup, with cheese croutons. While it is never not soup time, it is certainly soup time now. This has less to do with the weather, which is unpredictable as ever, and more to do with the fact that big pans of soup are easy to make, eager to please and roll easily into the next day, which is what I want as we roll into autumn. Lentils are wonderful, useful and good. High in protein, fibre and several members of the periodic table – phosphorus, magnesium and iron – lentils are also a valuable staple. They also cook in 30-40 minutes and don’t require soaking. (However, if you do soak them for a few hours in cold water, they will soften a bit, which reduces their cooking time and your energy bills). This is a basic recipe with additions that lift. The addition of anchovies is optional. A couple of fillets dissolved into the soffritto of onion, celery and carrot provide deep, salty seasoning, which somehow seems more meaty than fishy. Unless you are an anchovy hater, in which case you can probably spot one from a mile off. Instead, you could add a parmesan rind, ideally with the last of the cheese attached. Lentil-and-tomato soup Prep 5 min Cook 50 min Serves 4 6 tbsp olive oil 1 onion, peeled and diced 1 celery stick, peeled and diced 1 carrot, peeled and diced Salt A couple of anchovy fillets (optional) 300g brown lentils 500g peeled, crushed tomatoes (fresh or tinned) 3-4 sage leaves Parmesan rind (alternative to anchovies) Cubes of bread, salt, olive oil and grated parmesan, to make croutons In a large, heavy-based pan, warm the olive oil, then add the onion, celerycarrotand a pinch of salt. Fry until soft and turning translucent. Now , and only if you like them , add a couple of anchov y fillets and stir until they have dissolved into the vegetables. Add the lentils, stir until they glisten with oil, then tip in the tomato and sage. Simmer for a minute, then add 1.3 litres of water and the parmesan rind (but only if you haven’t used anchovies). Bring to a gentle boil, then reduce to a simmer for 40 minutes, or until the lentils are tender and have a thick consistency(you don’t want it to be stiff; if the soup seems too thick, add a little more water to loosen). Taste and add more salt and pepper as required. Rub the bread with olive oil and either bake or fry them (in which case you may need a bit more oil) until golden. Sprinkle the croutons with some grated parmesan and divide between bowls of the hot soup.