How to cook
Soak the peppers in water. Finely chop the onion. Leave it simmer in a deep bowl. Cut the leeks and add them as well. Season with salt and black pepper. Add the beans.
Wait for the mixture to thicken and remove from the heat. Strain the peppers and fill them with the bean stuffing.
Arrange in a baking pan and pour with olive oil. Bake the stuffed peppers at 360°F (180 degrees) for 30 minutes.