Prep the chicken: Pat the chicken thighs dry with paper towels. Season both sides generously with salt and pepper. Dry skin equals better browning and crispness.

Brown the thighs: Heat 1–2 tablespoons olive oil in a large oven-safe skillet or Dutch oven over medium-high heat. Place the chicken skin-side down and sear without moving until deeply golden, 6–8 minutes. Flip and cook 3–4 minutes more. Transfer to a plate. Do this in batches if needed.

Sauté the aromatics: Reduce heat to medium. Spoon off excess fat, leaving about 1–2 tablespoons in the pan. Add the onion with a pinch of salt and cook until soft and lightly golden, 4–6 minutes. Stir in the garlic and cook 30–60 seconds, just until fragrant.

Deglaze the pan: Pour in the wine or broth. Scrape up the browned bits with a wooden spoon. Let it simmer for 1–2 minutes to reduce slightly.

Build the sauce: Stir in crushed tomatoes, tomato paste, oregano, basil, thyme, and red pepper flakes if using. Season with 1/2 teaspoon salt and a few grinds of pepper. Taste and add a pinch of sugar if the sauce tastes too sharp.

Nestle in the chicken: Return the chicken to the pan, skin-side up. Spoon some sauce around (not on top) to keep the skin exposed and crisp. Bring to a gentle simmer.

Oven finish: Transfer the pan to a 375°F (190°C) oven. Cook 20–25 minutes, until the chicken reaches an internal temperature of 175°F (79°C) and is very tender.

Rest and finish: Remove from the oven and let rest 5 minutes. Taste the sauce and adjust seasoning with salt, pepper, and a drizzle of olive oil. Top with chopped basil or parsley and a shower of Parmesan.

Serve: Spoon the marinara and chicken over hot pasta or creamy polenta, or pair with crusty bread to mop up the sauce. Add a simple green salad to round it out.