Step 1: Season the chicken pieces with salt, pepper, and onion powder. Heat olive oil in a large skillet over medium-high heat and sear the chicken until golden brown on all sides (about 5-6 minutes). Remove chicken from the pan and set aside.
Step 2: In the same skillet, add the diced onion and sauté for 3 minutes until translucent. Add the minced garlic and cook for an additional minute until fragrant.
Step 3: Stir in the uncooked rice and toast for 2 minutes, stirring frequently. Pour in the chicken broth and bring the mixture to a boil. Reduce heat to low, cover with a tight-fitting lid, and simmer for 12 minutes.
Step 4: Remove the lid and quickly place the broccoli florets and the browned chicken on top of the rice. Replace the lid and continue to simmer for another 5-8 minutes, or until the liquid is absorbed and the broccoli is tender.
Step 5: Turn off the heat. Sprinkle the shredded cheddar cheese over the top and stir gently to combine. Let it sit covered for 2 minutes to allow the cheese to melt completely before serving.