Whisk together the flour, salt, black pepper and cayenne pepper in a bowl. In a separate shallow bowl, beat the egg. Place the panko crumbs into a third bowl.
Heat 2 tablespoons of olive oil in a frypan over medium heat. Dip each chicken tender into the seasoned flour then into the egg then roll in panko crumbs. Pan fry the chicken tenders until golden brown on both sides, about 4 minutes per side. Transfer the chicken pieces to a baking tray.
Heat 2 more tablespoons of olive oil in a frypan over medium heat and stir in the tomatoes, garlic, basil, onion and a pinch of salt and black pepper. Reduce heat and simmer the tomato sauce until it starts to thicken, stirring often, about 10 minutes. Spoon about 1 tablespoon of sauce over each chicken piece and top with a half piece of mozzarella cheese.
Bake in the preheated oven until the cheese is melted and bubbly, 8 to 10 minutes.