Preheat the oven to 425°F. Grease a large baking sheet with cooking spray or line the pan with aluminum foil for easy clean up.
In a large bowl, whisk together ¼ cup of the olive oil, the juice of one lemon, rosemary, garlic powder, and salt & pepper. Add the veggies to the bowl and give them a good toss. Arrange them onto the sheet pan.
Next, dip the chicken thighs into the sauce and place them onto the baking sheet; making sure to arrange the veggies around the chicken so that everything can cook evenly. Sprinkle with additional garlic powder and salt & pepper, if desired, and bake for about 30 to 35 minutes, or until the chicken is golden brown and has an internal temperature of 165°F.
When done, squeeze a couple of lemon wedges onto the finished dish and garnish with fresh rosemary! Enjoy!