Cut the chicken into uniform 1-inch pieces and season with salt and pepper. In a small bowl, combine garlic powder, onion powder, paprika, thyme, rosemary, and chili powder. Sprinkle half of this seasoning blend over the chicken and toss with half tablespoon olive oil until every piece is coated.

Heat 1 tablespoon olive oil in a large 12-inch skillet over medium-high heat until it shimmers and moves easily across the pan. Add the seasoned chicken in a single layer and cook for 6 to 8 minutes, stirring occasionally, until golden brown and cooked through to 165 degrees F internal temperature. Insert a thermometer into the thickest piece to confirm doneness. Transfer to a plate and set aside.

Add the remaining olive oil to the same skillet. Add the sliced onion and cook for about 2 minutes until it starts to soften and become fragrant.

Add broccoli, zucchini, and both bell peppers to the skillet. Sprinkle with the remaining seasoning blend and cook for approximately 5 minutes, stirring occasionally, until crisp-tender.

Pour in the chicken broth and use your spatula to scrape up all the browned bits from the bottom of the pan. Return the chicken and any accumulated juices to the skillet, stir everything together for 1 more minute, then remove from heat. Garnish with fresh parsley if desired and serve immediately.