Dice all the vegetables, thinly.
Heat the olive oil in a large pan, sautée the onion, add the red pepper, and the zucchini. Once al the vegetables are well done, set aside.
Whisk the eggs in a large bowl. Add the grated cheese, salt, pepper and nutmeg. If desired add the fresh cream. Mix well and incorporate the lentils and prepared vegetables. Mix thoroughly.
Roll out the puff pastry dough and line a 20 cm. round detachable baking pan.
Place the lentils mixture in the pastry covered pan.
Preheat oven a 170ºC Bake for about 40 minutes, or until the quiche is light brown.
Remove from the oven. Carefully remove from the baking pan. Serve hot.