There's a reason this combo never gets old — grilled chicken breast with roasted vegetables is the gold standard of high protein dinners. Season it right, and you've got a clean meal that actually tastes like you tried.
Preheat your oven to 425°F (220°C) and preheat your grill (or grill pan) to medium-high heat.
Pat the chicken breasts dry, brush lightly with 1 tbsp olive oil, and season on both sides with half the salt, black pepper, thyme, and oregano for even flavor distribution.
Cut zucchini into thick rounds, bell peppers and onion into chunks, and carrots into short sticks. Toss all vegetables with the remaining 2 tbsp olive oil, minced garlic, and the rest of the seasonings.
Spread the vegetables on a large, rimmed baking sheet in a single layer. Roast on the middle rack for 18–22 minutes, stirring once halfway, until vegetables are golden and just tender.
While vegetables roast, grill chicken breasts 5–6 minutes per side, only flipping once, until internal temperature reaches 165°F and juices run clear. Rest the chicken for 3 minutes before slicing. Serve sliced chicken atop the roasted vegetables.