Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Rinse the dry quinoa under cold water and place it in a small saucepan with 0.5 cup of water; bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes.
Place the broccoli florets and sliced red bell pepper on the prepared baking sheet and toss with 0.5 tablespoon of olive oil, 0.125 teaspoon of sea salt, and 0.125 teaspoon of black pepper.
Roast the vegetables in the oven for 20 minutes until they are tender and the edges are slightly charred and caramelized.
Season the chicken breast evenly on both sides with the garlic powder, dried oregano, and the remaining sea salt and black pepper.
Heat the remaining 0.5 tablespoon of olive oil in a large skillet over medium-high heat and sear the chicken for 6 to 7 minutes per side until the exterior is golden and the internal temperature reaches 165°F.
Remove the chicken from the skillet and let it rest on a cutting board for 5 minutes before slicing it into thin, even strips.
Assemble the meal by fluffing the quinoa with a fork and placing it in a bowl, then top with the roasted vegetables, sliced chicken, and fresh avocado slices before drizzling with the balsamic glaze.