In a bowl, season the chicken breasts with olive oil, dried oregano, smoked paprika, lemon juice, garlic, lemon slices, salt, pepper, and rosemary. Toss everything very well.
Cover the bowl with plastic wrap, and marinate for at least 30 minutes. Ideally, marinate the chicken for 2-3 hours if you can. Or, marinate overnight without adding the lemon juice and lemon slices. Then, 3 hours before cooking the chicken, add the lemon juice and lemon slices.
Preheat oven to 425ºF.
Flip the pieces, and bake another 10-15 minutes or until the chicken reaches an internal temperature of 165ºF.
Garnish with sprigs of fresh rosemary and slices of lemon.
If you make this recipe, please don't forget to snap a photo and hashtag it #primaverakitchen. I really want to see!