Pat the chicken thighs dry with paper towels. Season both sides with kosher salt and black pepper.
Heat the olive oil in a large skillet over medium-high heat until shimmering.
Place the chicken thighs skin-side down in the skillet. Cook without moving for 7-8 minutes until the skin is golden brown and crispy.
Flip the chicken thighs and cook for another 7-8 minutes until browned and cooked through (internal temperature should reach 165°F). Remove the chicken from the skillet and set aside on a plate.
Reduce the heat to medium. Add the minced garlic, chopped rosemary, and thyme to the skillet. Sauté for about 1 minute until fragrant, stirring constantly to prevent burning.
Pour in the chicken broth, lemon juice, and Dijon mustard. Stir to combine and scrape up any browned bits from the bottom of the skillet.
Let the sauce simmer for 3-4 minutes until slightly reduced and thickened.
Return the chicken thighs to the skillet, spoon some sauce over them, and cook for an additional 2 minutes to reheat and meld flavors.
Serve the chicken thighs hot with the pan sauce spooned on top.