Prepare chicken by slicing it thin and then pounding it out. Top it with 1 sage leaf and then a slice of prosciutto. Smack the prosciutto on to make it stick or thread it with a toothpick. Salt the chicken side and then dredge both sides in flour.
In a large frying pan, heat 1 tablespoon of olive oil to medium heat. Place chicken prosciutto side down for 1 minute and then flip to the chicken side and saute for about 5 minutes. Set chicken aside.
In the same frying pan, heat 1 tablespoon of olive oil. Add garlic and crushed red pepper and saute for 30 seconds. Add the tomato paste and combine. Saute for 30 more seconds. Add the peeled tomatoes, hand-crushing them or using a wooden spoon to gently break them apart. Bring to a simmer and add salt and 6-8 sage leaves. Simmer for 15 minutes.
Preheat oven to 375℉. In a large baking pan, coat a layer of sauce. Then place the chicken on top and lightly top with more sauce and slices of fresh mozzarella cheese. Bake for 10 minutes. Remove from the oven and serve.
Notes
Never dredge in flour ahead of time. The chicken will soak up some of the flour. and it won't fry as well.
I like to use fresh mozzarella for this recipe. But you could use shredded mozzarella and get similar results. The fresh mozzarella cooks quicker and has a more mild flavor.