Preheat: Preheat the oven by adjusting the temperature to 410°F (210°C).
Prepare the Sheet Pan: Line a baking tray with parchment paper.
Season the Veggies: in a big bowl, mix the cut bell peppers, onion, and corn with olive oil, dried thyme, and a sprinkle of sea salt. Make sure that all the vegetables are thoroughly covered.
Arrange the Veggies: Place the seasoned vegetables around the edge of the baking sheet, leaving room in the middle for the chicken.
Prepare the Chicken: Position the chicken thighs in the middle of the baking sheet. Add garlic powder, onion powder, cumin, smoked paprika, sea salt, and cracked pepper for seasoning.
Roast: Put the sheet pan in the oven and bake for 22-25 minutes, or until the chicken is fully cooked and the vegetables are still slightly crunchy.
Slice and Serve: After baking, take out the chicken from the oven and let it sit for a couple of minutes. Cut the chicken thighs into strips and remove the corn kernels from the cob.
Prepare Fajitas: Place the sliced chicken and roasted vegetables on whole wheat tortillas. Top with Greek yogurt, pico de gallo, and chopped cilantro.