Heat an oven-safe pot over medium-high heat; stir rice and 2 tablespoons oil together in the hot saucepan to coat the rice with oil. Pour hot water over the rice; bring to a boil and place a cover on the pot.
Bake rice in preheated oven until the water is absorbed and rice is tender, 12 to 15 minutes.
Place broccoli into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, 5 to 7 minutes. Drain and season broccoli with salt and pepper.
Heat remaining oil in a skillet over medium-high heat; add chicken to hot oil, season with garlic powder and onion powder. Saute chicken until completely browned, 5 to 7 minutes.
Stir onion into the chicken; continue cooking until onions are soft and translucent, 5 to 7 minutes.
Spoon rice into the skillet; cook until lightly browned on the bottom, about 3 minutes. Stir broccoli into the rice mixture; sprinkle lemon zest and lemon juice over the mixture and stir. Top with Parmesan cheese.
