Prepare and Sear the Chicken
Pat chicken thighs dry with paper towels and season generously with salt and pepper on both sides. Heat olive oil in a large skillet or Dutch oven over medium-high heat. Brown the chicken for 3-4 minutes per side until golden. Remove and set aside on a plate.
Sauté the Vegetables
In the same pan, add a little more oil if needed. Add sliced onions and bell peppers. Cook for 6-8 minutes, stirring occasionally, until softened and slightly caramelized.
Add Garlic and Deglaze
Stir in minced garlic and cook for 30 seconds until fragrant. Pour in the white wine (or chicken broth) and scrape up all the flavorful browned bits from the bottom of the pan.
Simmer with Tomatoes
Add crushed tomatoes and herbs to the pan. Stir to combine. Return the chicken to the pan, nestling it into the sauce skin side up. Cover and reduce heat to low. Simmer for 30-35 minutes until chicken is tender and cooked through (internal temperature of 165°F).
Finish and Serve
Taste the sauce and adjust seasoning with additional salt, pepper, or red pepper flakes if desired. Garnish with fresh parsley. Serve hot with your choice of sides.