Follow these simple steps to create your Easy One Pan Italian Chicken In Tomato Sauce:

1. Heat Oil: In a large skillet, heat the olive oil over medium-high heat.
2. Sear Chicken: Season the chicken thighs with salt and pepper. Place them skin-side down in the hot skillet. Sear for about 5-7 minutes, or until golden brown. Flip and sear for another 5 minutes. Remove the chicken and set it aside.
3. Sauté Onions and Garlic: In the same skillet, add the diced onion and sauté until translucent, about 3-4 minutes. Add the minced garlic and sauté for an additional minute until fragrant.
4. Add Tomatoes and Spices: Stir in the crushed tomatoes, dried oregano, dried basil, and red pepper flakes (if using). Allow the mixture to simmer for a couple of minutes, stirring occasionally.
5. Return Chicken to Skillet: Nestle the seared chicken thighs back into the skillet, skin-side up. Spoon some of the sauce over the chicken.
6. Simmer: Reduce the heat to low, cover the skillet, and let it simmer for about 30 minutes, or until the chicken is cooked through and tender.
7. Check for Doneness: The internal temperature of the chicken should reach 165°F (75°C). If not done, allow an additional 5 minutes of cooking time.
8. Serve: Remove from heat and garnish with fresh basil leaves and grated Parmesan cheese if desired.