Preheat oven to BROIL. Lightly spray chicken breasts with cooking oil.
In a small mixing bowl combine basil, oregano, garlic powder, onion powder, sweet paprika, salt, and pepper. Rub the chicken breasts with the seasoning mix.
Heat vegetable oil and ½ tablespoon butter in a large, 12-inch oven-safe skillet set over medium heat. Add chicken to the hot oil and cook for 5 to 7 minutes on each side, or until cooked through and browned. Cooking time depends on the thickness of the chicken breasts. Chicken is cooked through when internal temperature registers at 165˚F. Use an Instant Read Thermometer for accuracy. Remove cooked chicken from skillet and set aside; keep covered.
Add remaining butter to the skillet and melt over medium heat. Add onion and cook for 2 minutes, or until it starts to soften. Stir in garlic and cook for 20 seconds, or until fragrant.
Add tomatoes; increase heat to medium-high, and continue to cook for 4 to 5 minutes, or until tomatoes break down and release their juices. If using canned tomatoes, cook until heated through and bubbling.
Stir in chicken broth or wine; cook for 3 minutes. Add spinach and cook for a minute, or until spinach is wilted. Transfer chicken breasts back to the skillet. Top each chicken breast with shredded cheese.
Broil in the oven for 2 to 3 minutes, or until cheese is melted. Remove from oven. Garnish with parsley and serve.
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.