Put the beans into a stockpot with enough water just to cover and bring to a boil.
Drain half of the water after beans are tender. Return beans to stockpot and add onion, tomato, olive oil, cumin, parsley, lemon juice, salt and pepper. Mash the beans and bring the mixture back to a boil, then reduce the heat. Gently cook the mixture for 5 minutes. Serve warm with toasted pitta.