Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Chop the broccoli into bite-sized florets, slice the red bell pepper into thin strips, and slice the zucchini into half-moons.
In a large bowl, toss the vegetables with 0.5 tablespoons of olive oil and half of the sea salt, black pepper, and dried oregano.
Spread the vegetables in a single layer on the baking sheet and roast for 18-20 minutes until tender and slightly caramelized.
While the vegetables roast, season the chicken breast on both sides with the remaining salt, pepper, and garlic powder.
Heat the remaining 0.5 tablespoons of olive oil in a skillet over medium-high heat.
Place the chicken in the hot skillet and sear for 5-7 minutes per side until the internal temperature reaches 165°F and the exterior is golden brown.
Remove the chicken from the pan and let it rest for 3 minutes before slicing to ensure it stays juicy.
Serve the sliced chicken alongside the roasted vegetables and finish with a fresh squeeze of lemon juice.