Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
In a large bowl, toss the broccoli florets, bell pepper strips, and zucchini slices with half of the olive oil and a pinch of salt and pepper.
Spread the vegetables in a single layer on the prepared baking sheet and roast for 15-20 minutes until they are tender and slightly charred.
While the vegetables roast, season the chicken breast evenly on both sides with the sea salt, black pepper, and dried oregano.
Heat the remaining olive oil in a heavy-bottomed skillet over medium-high heat until shimmering.
Place the chicken in the skillet and sear for 5-7 minutes per side, or until the exterior is golden brown and the internal temperature reaches 165°F.
Add the minced garlic to the pan during the last minute of cooking, stirring constantly to prevent burning while releasing its aroma.
Drizzle the fresh lemon juice over the chicken, then plate it alongside the roasted vegetables and serve immediately.