Heat the olive oil in a large skillet or Dutch oven over medium-high heat. Once the oil is hot, add the chicken thighs, skin-side down, and cook for about 5-7 minutes on each side until golden brown. This step is essential for locking in the flavor and creating a crispy, golden exterior. Remove the chicken from the pan and set it aside.

In the same pan, add the chopped onion and red bell pepper. Sauté for about 4-5 minutes until softened and slightly caramelized. This step will bring out the natural sweetness of the vegetables, adding depth to the sauce.

Stir in the minced garlic, dried oregano, dried basil, and red pepper flakes (if using). Cook for another 1-2 minutes, allowing the garlic to become fragrant. These spices create the aromatic base that defines the dish.

Pour in the diced tomatoes, chicken broth, and a pinch of salt and pepper. Stir everything together, scraping up any browned bits from the bottom of the pan. These bits are full of flavor and will enrich the sauce.

Return the browned chicken thighs to the pan, skin-side up. Spoon some of the sauce over the chicken and reduce the heat to low. Cover the pan and let the chicken simmer for 30-40 minutes until the chicken is fully cooked and tender. The low and slow cooking will allow the chicken to absorb all the wonderful flavors of the sauce.

Once the chicken is cooked through, check the seasoning and adjust with more salt and pepper if needed. Garnish with freshly chopped parsley for a burst of color and freshness. Serve it hot, and enjoy the comforting, savory goodness of Chicken Cacciatore!