Preheat the oven to 425°F (220°C).
Line a large sheet pan with parchment paper or lightly grease it.
Place the potatoes and carrots on the sheet pan.
In a small bowl, combine olive oil, garlic, thyme, oregano, rosemary, salt, and pepper.
Drizzle half of the seasoning mixture over the vegetables and toss to coat.
Arrange the chicken thighs on top of the vegetables.
Brush the remaining seasoning mixture over the chicken.
Scatter the lemon slices around the pan.
Bake for 40 to 45 minutes, or until the chicken reaches an internal temperature of 165°F (74°C).
For extra crispy skin, broil for 2 to 3 minutes at the end of cooking.
Let rest for 5 minutes before serving.