If you're making homemade pesto, start with that. In the recipe notes you will find a recipe for basil parsley almond pesto, and many other kinds.
Cut mozzarella into slices and tomatoes into smaller pieces.
Prepare the chicken: if having small chicken breasts, simply pound them slightly in their thickest part (when a piece of meat is more uniformly sized, its thinner part won't be overcooked). If having large chicken breasts, place them on a chopping board and cut them horizontally in half - now you should have two thinner fillets. You will need 4 chicken fillets for this recipe.
Season the chicken: Pat dry the chicken with paper towels. Season the chicken on both sides with salt, pepper, garlic powder, and Italian seasoning. Dredge in flour on all sides.
Cook the chicken: heat oil in a large frying pan over medium-high heat. Cook chicken on one side until well-browned then turn over. Place mozzarella slices on top of the chicken and cook until the chicken is cooked through and the cheese melted (if the cheese is melting too slowly, you can close the pan with a lid, if using thin slices of low-moisture mozzarella - it's enough for the cheese to melt to just place the cheese at the end of the cooking time on the hot chicken).
Take the chicken off the pan, spread with pesto, and top with chopped cherry tomatoes. Season tomatoes lightly with salt and pepper.
Enjoy!