Heat olive oil in a large skillet or Dutch oven over medium-high heat until shimmering.
Add chicken cubes, salt, and pepper; sauté until chicken is browned and cooked through, approximately 6 minutes. Remove chicken from the pan and set aside.
Add the dry orzo to the skillet and toast for 1 minute, stirring constantly to prevent burning.
Pour in the chicken broth and bring to a rapid boil. Reduce heat to low, cover, and simmer for 8 minutes.
Place broccoli florets on top of the orzo, cover again, and cook for an additional 4 minutes until the broccoli is bright green and the liquid is mostly absorbed.
Return the cooked chicken to the skillet. Stir in the garlic powder, heavy cream, and shredded cheddar cheese.
Stir continuously over low heat until the cheese is fully emulsified into a smooth sauce and the orzo is tender.
Adjust seasoning to taste and serve immediately.