Heat 1 tablespoon of oil in a saucepan and briefly sauté the lentils in it. Season with cumin and pepper and add 300 ml water. Bring to the boil, cover and cook for 8-10 minutes. Stir several times. Peel shallots and cut into fine rings.
Remove the lentils from the stove and season with salt and pepper. Pour into a bowl, add the shallots.
Whisk mustard with thick juice and vinegar, season with salt and pepper. Beat 4 tablespoons of oil in a thin stream. Mix into the lentils. First cut the tofu into thin slices. Cut the slices diagonally in half.
Heat 2 tablespoons of oil in a frying pan. Fry the tofu for 1-2 minutes on each side, remove.
Wash and clean the lamb's lettuce and drain well. Cut cress from the bed. Shortly before serving, mix lamb's lettuce and tofu into the lentils, season to taste. Serve sprinkled with cress.