Pat the chicken thighs dry, season with salt, pepper, and garlic powder, then lightly coat with flour. Brown the chicken in olive oil for 5–6 minutes per side until golden and crisp before setting aside.
Cook the onions, bell peppers, and mushrooms in the same pan for 8–10 minutes until softened and lightly caramelized. Add minced garlic and cook briefly until fragrant.
Stir in tomato paste and cook for 1 minute. Deglaze the pan with red wine or broth, scraping up the browned bits before adding crushed tomatoes, chicken broth, and dried herbs.
Return the chicken to the pan and simmer partially covered over low heat for 35–40 minutes until the chicken becomes tender and fully cooked through.
Taste and adjust seasoning before garnishing with parsley, basil, and Parmesan cheese. Serve hot with pasta, mashed potatoes, or bread.