Preheat the oven to 400F. Spray a casserole dish with oil.

Pound chicken breasts to thin them out a little bit, season them with garlic powder, onion powder, oregano, chili pepper flakes salt, and black pepper. Go easy on the salt as other ingredients will have it. Place chicken breasts inside the casserole dish.

Place a skillet over medium-high heat. Add in the butter and let it melt. Add in the onions and cook them until they're caramelized, occasionally giving them a stir. Once the pan starts getting dry, pour in the chicken broth to prevent it from burning, continue stirring until the onions brown up fully.

Finally, add in the minced garlic and cook for 30s until fragrant. Remove from heat and the onion cool down for 5 minutes.

Take the caramelized onion and place it on top of each chicken breast, covering them. Sprinkle with mozzarella cheese and bake in the oven for 20-25 minutes. The cheese should be bubbling and, most importantly, the chicken breasts should be fully cooked.

Broil for 2 minutes so the cheese turns slightly golden. Remove from the oven and garnish with fresh parsley before serving.