Season the chicken with about 1 teaspoon salt, black pepper, 1 teaspoon oregano, and the garlic powder.
Heat 1 tablespoon olive oil in a large deep skillet or braiser over medium-high heat. Sear the chicken for 3–4 minutes per side, until golden. Transfer to a plate.
Add the remaining olive oil, peppers, and red onion with a small pinch of salt. Cook for 4–5 minutes, until beginning to soften.
Add the garlic, remaining ½ teaspoon oregano, and lemon pepper. Cook for about 30 seconds. Stir in the orzo and cook for 1 minute.
Add the chicken broth and 1 tablespoon lemon juice, scraping up the browned bits from the bottom of the pan. Bring to a simmer.
Nestle the chicken back into the pan along with any accumulated juices. Cover and cook over medium-low heat for 8–10 minutes, stirring the orzo once or twice, until the chicken reaches 165°F and the orzo is al dente. Add a splash more broth if needed.
Remove from the heat and stir in another 1–2 tablespoons lemon juice. Taste and adjust salt and black pepper.
Finish with crumbled feta, fresh parsley, and another crack of black pepper.