Between pieces of plastic wrap or waxed paper, place each chicken breast smooth side down; gently pound with flat side of meat mallet or rolling pin until about ¼ inch thick.
In shallow medium bowl or pie plate, mix bread crumbs, cheese, salt and pepper.
Coat chicken with crumb mixture, pressing to coat well on both sides.
In 12-inch nonstick skillet, heat 2 tablespoons of the oil over medium-high heat.
Cook chicken in oil 6 to 10 minutes, turning once, until golden brown on outside and no longer pink in center.
Remove chicken from skillet; cover to keep warm.
To skillet, add remaining 1 tablespoon oil, 2 cups of the tomatoes, the onions and garlic; cook and stir 2 minutes.
Stir in vinegar; cook 30 seconds longer.
Remove from heat; stir in remaining 1 cup tomatoes and the oregano.
Serve over chicken.
Garnish with additional fresh oregano sprigs, if desired.
Notes / Tips / Wine Advice:
Panko bread crumbs are coarser than regular bread crumbs. With a bit of pressing, the coating sticks to the chicken on its own, making this chicken very crunchy, yet light too.