Preheat the oven to 400°F (200°C).
Pat the chicken thighs dry with paper towels. Rub each thigh with 1 tablespoon olive oil, then season evenly with salt, black pepper, dried thyme, and dried rosemary.
In a large oven-safe pot or Dutch oven, heat the remaining 1 tablespoon olive oil over medium heat on the stovetop.
Add the chicken thighs skin side down and sear for 4-5 minutes until the skin is golden brown. Flip and sear the other side for 2 minutes. Remove chicken from the pot and set aside.
Add the garlic cloves, onion wedges, carrots, and potatoes to the pot. Stir and cook for 3-4 minutes to slightly soften the vegetables.
Pour in the chicken broth and scrape the bottom of the pot to release any browned bits.
Return the chicken thighs to the pot, placing them on top of the vegetables. Arrange lemon slices over the chicken and vegetables.
Cover the pot with a lid or aluminum foil and transfer it to the preheated oven.
Bake for 35 minutes covered, then remove the lid or foil and bake for an additional 10 minutes uncovered to crisp the chicken skin.
Remove the pot from the oven and let it rest for 5 minutes before serving.