Place the chicken breasts in a Ziploc bag and tenderize on both sides. Preheat oven to 375 degrees.
In a medium frying pan, brown both sides of the chicken breasts in 2 Tbsp. olive oil; season with salt and pepper (or your favorite seasoning). Set aside.
Add 2 Tbsp. more olive oil to the hot pan and sauté the red onion for about 5 minutes until tender and caramelized.
Lay the chicken in a prepared (sprayed) baking pan; layer cheese slices on top of the breasts.
Spread about 1 cup (or more) sour cream on top of cheese; sprinkle with chopped olives and fresh thyme.
Cover the dish with foil and bake at 375 degrees for 30 minutes. Delicious served on brown rice!