Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Chop the red bell pepper and zucchini into uniform, bite-sized pieces.
In a large bowl, toss the broccoli florets, bell pepper, and zucchini with 0.5 tablespoons of olive oil, half of the sea salt, and half of the black pepper.
Spread the vegetables in a single layer on the prepared baking sheet and roast for 18-20 minutes until tender and slightly charred.
While vegetables roast, season the chicken breast evenly with garlic powder, dried oregano, and the remaining salt and pepper.
Heat a grill or grill pan over medium-high heat and lightly brush with the remaining 0.5 tablespoons of olive oil.
Grill the chicken for 6-7 minutes per side, or until the internal temperature reaches 165°F.
Remove the chicken from the heat and let it rest for 5 minutes before slicing into strips.
Plate the roasted vegetables, top with the sliced chicken, and drizzle the fresh lemon juice over the entire dish before serving.