01 - Preheat oven to 400°F (200°C).
02 - Place chicken breasts between sheets of parchment paper and gently pound with a meat mallet to an even thickness of about ½ inch. Season both sides generously with salt and black pepper.
03 - Dredge each seasoned chicken breast in all-purpose 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 breasts for 2 to 3 minutes per side until lightly golden. Remove from skillet and set aside.
05 - In the same skillet, add the finely chopped shallot and minced garlic. Sauté for about 1 minute until fragrant and softened.
06 - Deglaze the skillet with dry white wine, scraping up any browned bits from the bottom. Stir in the crushed tomatoes, chicken broth, and dried oregano. Simmer for 5 minutes to allow the flavors to meld.
07 - Nestle the seared chicken breasts back into the sauce. Top each breast with a slice of prosciutto di Parma and a layer of sliced Fontina cheese.
08 - Transfer the skillet to the preheated oven and bake for 10 to 12 minutes, until the Fontina is melted and bubbly and the chicken is cooked through to an internal temperature of 165°F.
09 - Remove from oven, garnish with fresh basil leaves, and serve hot with extra sauce spooned over each portion.