- Preheat oven to 400°F 
- In a cast iron skillet, warm up the olive oil on medium heat - 3 tbsp olive oil 
- While the oil is heating up, using half the salt and pepper and all of the oregano, season all sides of each chicken breast. - 1 tsp dried oregano, ¼ tsp salt, ¼ tsp ground black pepper, 2 chicken breast 
- Place the chicken breast in the hot skillet and cook for 5 minutes. 
- While the chicken is cooking, wash and cut the asparagus spears into 1-inch pieces, dice the onion and mince the garlic. - 1 bunch of asparagus, ¼ cup red onion, 1 clove garlic 
- After 5 minutes, turn the chicken then add the asparagus, onions, tomatoes and olives. Sauté for another 5 minutes. - 1 bunch of asparagus, 1 cup grape or cherry tomatoes, ¼ cup red onion, ¼ cup kalamata olives 
- Add minced garlic and cook for 30 seconds until fragrant. - 1 clove garlic 
- Add chicken stock and the remaining salt and pepper to the skillet and place in the oven. Bake uncovered for 15 minutes. - ½ cup chicken stock, ¼ tsp salt, ¼ tsp ground black pepper 
- Add crumbled feta cheese and bake for another 5 minutes or until the chicken reaches a minimum internal temperature of 165°F. - ½ cup feta 
- Serve as is or on top of rice or quinoa.