Salt and pepper the chicken on both sides. Sauté in olive oil over medium heat until light brown on each side. Transfer to a plate and set aside.
Add the bell pepper, onion, and garlic, crushed red pepper, and oregano and cook until tender, about 10 minutes. Season with salt and pepper.
Add the tomatoes with their juice, chicken stock, red wine, capers and oregano. Return the chicken to the pan and coat in the sauce. Add the rosemary. Bring the sauce to a simmer over low heat and cook for about 10 minutes. Transfer to a platter, sprinkle with basil and serve.