Season the chicken: Pat the chicken breasts dry with a paper towel. Season both sides with salt, pepper, garlic powder, onion powder, dried oregano, and paprika.
Cook the chicken: Heat olive oil in a large skillet over medium heat. Add the chicken breasts and cook for 5–6 minutes per side, or until golden brown and cooked through (internal temperature of 165°F or 74°C). Remove the chicken from the skillet and set aside.
Sauté the vegetables: In the same skillet, add the zucchini, red bell pepper, yellow bell pepper, and cherry tomatoes. Cook for 5–7 minutes, stirring occasionally, until the vegetables are tender but still vibrant.
Add spinach and broth: Stir in the baby spinach and pour in the chicken broth (or water). Simmer for 2–3 minutes, allowing the spinach to wilt and the flavors to meld.
Return the chicken: Place the cooked chicken breasts back into the skillet, nestling them among the vegetables. Drizzle with fresh lemon juice and cook for an additional 1–2 minutes to reheat and coat with the pan juices.
Garnish and serve: Sprinkle the dish with fresh parsley for a burst of flavor and color. Serve warm as is, or pair with rice, quinoa, or whole-grain bread for a more filling meal.