Season the drumsticks evenly with sea salt, freshly cracked pepper, and garlic powder, to taste. Place them uncovered into the refrigerator until you're ready to eat (mine were in the refrigerator for close to 2 hours). Remove the chicken from the refrigerator 15 minutes prior to cooking so it can come to room temperature.
Preheat the oven to 400 degrees.
Place the fingerling potatoes into a pot of boiling water and cook until fork-tender, about 5 minutes. Drain and let cool. Once the potatoes are cool to the touch, slice them in half lengthwise then toss them into a bowl. Add the grape tomatoes, zucchini, mushrooms, and onions to the bowl. Drizzle with olive oil then season with garlic powder, sea salt, and freshly cracked pepper, to taste; toss to coat evenly.
Heat a large Dutch oven coated in cooking spray over medium-high heat. Add the drumsticks to the HOT Dutch oven and cook for 4-5 minutes then flip the drumsticks over. Remove from the heat and place the veggies around the chicken; add the sprig of fresh thyme then place into the oven.
Roast for 15 minutes then stir the veggies. Continue to roast for an additional 10-15 minutes. Remove from the oven and toss the veggies so they are coated in the wonderful pan juices. Serve. Enjoy.