Heat the olive oil in a large OVEN PROOF Dutch oven over medium high heat. Remove any excess fat from the thighs then season both sides with sea salt, freshly cracked pepper, and garlic powder, to taste. Place the chicken, skin side down, in the hot pan. Cook for 6-7 minutes or until the chicken is golden brown. Carefully, tilt the pan and remove all the oil (this will make the dish healthier and also will prevent the veggies and chicken from being greasy). Once all the oil is gone from the pan, flip the chicken over and move over to one side of the pan. Add the asparagus and grape tomatoes to the other side of the pan then season lightly with sea salt and freshly cracked pepper, to taste. Place into the oven and cook for 25 minutes, or until chicken has cooked through.