Place about 1 cup of compressed sliced prosciutto in a food processor. Add 1/2 of garlic clove and about 1/3 cup of olive oil. Puree till smooth. Add about 1/2 cup of bread ( no crust, use only the enterior).Continue to puree and put aside when smooth. -

Sautée 2 sliced onions till very soft. Season with salt and pepper. Put aside.

Cut an average filet of red snapper in 1/2 and then butterfly both fillets of fish. Place a good amount of prosciutto spread in the center and close top flap.Repeat with other filets.

In a large bowl, mix 75% fine polenta with 25% breadcrumbs.Season a little salt and pepper. Not to much due to the prosciutto stuffing having a lot of salt.Repeat with other stuffed filets.

Place top side of fillet down in the polenta mix and press so it sticks well to the fish.

Using a non stick frying pan, add a good layer of olive oil and heat. Place the fish filet breaded side down and allow to become crispy. Remove the fish with a spatula and place on flat baking pan. Repeat with other filets.

Preheat oven to 375 and bake about 8 minutes or until fish is ready. 

For the Sauce: In the meantime frying pan saute a little chopped onion with butter until golden.Add some capers and some heavy cream and bring to a low boil. Add a good amount of mustard and stir using a wooden spoon until sauce becomes smooth.Add a good amount of fresh ground pepper and taste for seasoning. 

When serving add some sauce on the bottom of dish, add some sauteed onions and then the filet. Slice a bit of prosciutto to add some color with a spring of parsley.