Season the chicken with salt and pepper. Dredge the chicken in the flour so that it is lightly coated. (Read more about this here.)
1 pound boneless skinless chicken thighs, 1 teaspoon kosher salt, 1/4 teaspoon black pepper, 1/2 cup all purpose flour
Heat the oil in a large skillet over medium-high heat. Brown the chicken on both sides, about 3 minutes per side. Remove the chicken from the skillet and set aside.
2 tablespoons olive oil
Turn the heat down to medium heat. Add the garlic, onion, mushrooms, and peppers to the skillet. Sauté until the onion is translucent, about 5 minutes.
4 garlic cloves, 1 yellow onion, 1 red bell pepper
Add the wine to the pan and deglaze the pan. Stir in the tomatoes, oregano, and capers. Return the chicken to the pan. Bring to a boil and then reduce to a simmer. Cover and continue cooking for 20 minutes. After 20 minutes, cook uncovered for 5 minutes.
1/2 cup red wine, 15 ounces crushed tomatoes, 1 teaspoon dried oregano, 2 tablespoons capers
Serve over spaghetti with fresh parsley and freshly grated parmesan cheese.