Heat olive oil in a large skillet or Dutch oven over medium heat. Add ground beef, break it apart with a wooden spoon, and cook for 5–7 minutes until browned. Drain excess fat if needed.

Add diced onion, bell pepper, and celery to the beef. Cook for 3–5 minutes until softened, stirring occasionally. Add minced garlic and cook for 1 minute until fragrant.

Stir uncooked long-grain rice into the beef and veggie mixture, coating each grain in oil and seasonings. Toast lightly for 1–2 minutes to deepen the flavor.

Sprinkle in smoked paprika, dried thyme, Cajun seasoning, and black pepper. Pour in chicken broth, stir, and bring to a boil.

Reduce heat to low, cover tightly, and simmer for 18–20 minutes without lifting the lid.

Remove from heat, keep covered for 5 minutes, then fluff with a fork. Top with chopped green onions and serve hot.