Rinse lentils and boil with 750 ml (approximately 3 cups) of water and simmer covered for about 30 minutes. Once the lentils are cooked, turn off the heat, stir in the bulgur and leave for approximately 10 minutes.
Rinse, trim and finely chop the white and green parts of the scallion.
Heat oil in a pan and sauté the finely chopped scallion, then add tomato paste and sauté briefly. Remove from heat and stir in the bulgur and lentil mixture. Allow to cool. Add the parsley. Season with lemon juice, salt, pepper and chile powder. Form the mixture into small balls and arrange in a bowl with lettuce leaves and lemon wedges.