For the soup
Brown the onion and the leek in olive oil.
Then add the chopped marrow, stir and add the flour and the stock.
Season with salt and pepper.
Bring to the boil and simmer until cooked; then purée and strain the soup. Set aside.
For the breaded skins
Roll the skins into balls.
Coat these in flour, then in beaten egg and finally in the Quely Picada biscuit crumbs mixed with the sesame.
Fry in oil, drain and set aside.
Assembly of the dish
Serve the soup in a deep bowl, add the marrow skin balls, and the Quely Picolines and decorate with the mixed sprouts.