01 - Preheat oven to 400°F.
02 - Place chicken breasts between sheets of parchment paper and gently pound to an even thickness of about ½ inch. Season both sides generously with salt and black pepper.
03 - Dredge each chicken breast in flour, shaking off any excess to ensure a light, even coating.
04 - Heat olive oil in a large oven-safe skillet over medium-high heat. Sear chicken for 2 to 3 minutes per side until lightly golden. Remove and set aside on a plate.
05 - In the same skillet, add shallot and garlic. Sauté until fragrant, about 1 minute, stirring to prevent burning.
06 - Deglaze the pan with white wine, scraping up any browned bits from the bottom. Add crushed tomatoes, chicken broth, and dried oregano. Stir to combine and simmer for 5 minutes until the sauce slightly thickens.
07 - Lay the seared chicken breasts back into the sauce. Top each breast with a slice of prosciutto and an even layer of Fontina cheese.
08 - Transfer the skillet to the oven and bake for 10 to 12 minutes, until the cheese is fully melted and the chicken registers an internal temperature of 165°F.
09 - Remove from the oven, garnish with fresh basil leaves, and serve hot with extra sauce spooned over the top.