1/4 cup extra-virgin olive oil
2 garlic cloves, minced
Pinch of crushed red pepper flakes
1 28-ounce can tomatoes, lightly pulsed in a blender or food processor
2 teaspoons coarse salt
3 pounds boneless, skinless chicken breasts (3 whole breasts, split down the middle)
1/2 cup plain breadcrumbs
3/4 cup freshly grated Parmesan cheese
1/4 teaspoon freshly ground black pepper
1 tablespoon unsalted butter, plus more if needed
1 1/2 pounds fresh mozzarella cheese, sliced thin