Put chickpeas in a stockpot with twice as much water as beans and let soak overnight at room temperature. Place a sliced lemon in a pitcher of water and let soak overnight.

When the beans are wrinkled from soaking, cook them until tender, about 1 hour, then drain them thoroughly and put back in the stockpot. Add 2 tablespoons olive oil, chopped scallion, pepper and ground cumin. Cook on high for a minute or two, stirring constantly. This will enhance the flavor. Put the beans and stock in a blender or food processor. Add salt, pepper, garlic and olive oil. Puree well, scraping the sides of the jar occasionally for a smooth consistency. Add tahini paste, freshly squeezed lemon juice and, if necessary, water in which the sliced lemon had been soaking. Hummus needs to be smooth, but not too thin. Keep it in a fridge, in a covered container, up to five days.

Arrange on a plate with pita bread, crackers of falafel. Just before serving, drizzle with olive oil and sprinkle with chili powder.