In a large pan pour the extra virgin olive oil, two cloves of garlic, the chili pepper and a glass of white wine.
Wash and clean the mussels thoroughly, scraping them under water. Eliminate broken or open ones. Place the mussels in the pan. Cover and light the fire, cook over high heat for 5 minutes and then lower the flames and put a lid on the pan. Mussels will be ready when they are opened.
Put the breadcrumbs, salt, pepper, parsley and chives in a bowl, add the extra virgin olive oil and mix well.
Remove the shell from the mussels where the shellfish is not attached, place the shells in the mussels in a baking dish and cover with the breadcrumb mixture. Bake for about 10 minutes.
The mussels au gratin are ready to be served.