In the meantime, clean and wash the leek and cut into thin rings, finely dice the peppers and tomatoes. Put plenty of olive oil in a large pan and fry the chopped vegetables in it. Add the squeezed garlic and fry briefly, then add the tomato paste, a little sugar and the spices and season well while stirring constantly.
Drain the cooked spaghetti, add to the pan and mix well.
Serve with a fresh salad and possibly grated cheese.