Make the tomato sauce: In order to make the sauce smooth, if it's not too much work for you, crush the canned tomatoes as shown here.
Put the olive oil and garlic in a small pan and cook over low heat until fragrant. Add the juice and tomatoes from Step 1 plus a little salt and the bay leaf, and simmer without covering with a lid.
After simmering for about 10 minutes, thicken to your preferred consistency. Taste, and add more salt if needed.
Prepare the chicken: Butterfly out the thick parts of the chicken breast. Bash out the meat so that it's about 5mm in thickness all over.
Spread the basil sauce over the chicken and top with sliced mozzarella cheese. Season with salt and pepper. If you don't have any basil paste, fresh basil leaves are fine too.
Fold the part of the chicken without cheese on top of the part with cheese, and dust the chicken with flour.
Cook the chicken: Heat up the butter and olive oil in a frying pan and brown both sides of the chicken from Step 6. Turn the heat down to low and cook the chicken through.
Finish: Spread the tomato sauce on a plate, place the cut up chicken from Step 7 on top, and optionally pour more sauce over the top. Enjoy.
Added note: If the chicken won't cook through, try browning it in Step 7 and then grilling it in the oven.
Story Behind this Recipe
I wondered if I could make an elegant western style dish using the chicken breasts, mozzarella cheese and basil paste I had on hand. I got the idea of serving tomato sauce on the side from the roast chicken with tomato sauce I had at a restaurant the other day.
To prevent the cheese from leaking out while the chicken is being cooked, wrap the cheese in Step 6 so that you can't see the cheese. After sautéing, lid and let rest. The chicken will be easier to cut this way. You can store the sauce in the freezer and use it in pasta and pizza dishes.