In a frypan with oil fry the potatoes and carrots until they start to brown. Arrange the thigh pieces in a casserole dish then add the onion and browned potatoes and carrots.
Combine the lemon juice, garlic, thyme, salt and pepper with the 1/2 cup of oil then pour this mixture over the chicken and potatoes.
Bake in the preheated oven for 60 minutes, basting the chicken and potatoes with the sauce mixture. When cooked through remove from the oven and rest for 5 minutes before serving.