Preheat the oven: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it with olive oil.

Prepare the garlic butter marinade: In a small bowl, whisk together the melted butter, minced garlic, rosemary, thyme, paprika, Dijon mustard (if using), salt, and pepper.

Coat the chicken thighs: Pat the chicken thighs dry with paper towels. Rub the garlic butter mixture all over the chicken thighs, making sure to get under the skin for extra flavor.

Roast the chicken: Place the chicken thighs skin-side up on the prepared baking sheet. Roast in the preheated oven for 35-40 minutes, or until the skin is crispy and the internal temperature reaches 165°F (75°C).

Serve: Remove from the oven and let the chicken rest for a few minutes. Serve hot with lemon wedges on the side and garnish with fresh parsley. This dish pairs well with roasted vegetables or cauliflower mash for a complete keto-friendly meal.