Whisk together the olive oil, lemon juice, minced garlic, oregano, thyme, Dijon mustard, salt, pepper, and red pepper flakes in a bowl until well combined. Pat the chicken thighs dry with paper towels to help them absorb the marinade better, then place them in a large bowl or zip-top bag. Pour the marinade over the chicken, making sure each thigh is well coated. Cover and refrigerate for at least 1-2 hours, or up to 8 hours for deeper flavor—the acid from the lemon juice will gently tenderize the meat while the garlic and herbs infuse throughout.

Preheat your oven to 350°F. Transfer the marinated chicken thighs and all the liquid to a 9x13 inch baking dish, arranging them skin-side up so the skin can crisp as it roasts. Bake for 40-45 minutes until the chicken reaches an internal temperature of 175°F when measured at the thickest part of the thigh (avoiding the bone). I like to tent the dish loosely with foil for the first 20 minutes if the skin is browning too quickly, then uncover to allow the skin to crisp up during the final 20-25 minutes.

For extra crispy, golden skin, turn on the broiler and place the baking dish on the top rack for 2-3 minutes, watching carefully to prevent burning. Remove from the oven and let the chicken rest for 5 minutes before serving—this allows the juices to redistribute throughout the meat, keeping it moist and tender. Spoon some of the pan juices over each thigh before plating.