Heat olive oil in a large skillet over medium heat.
Add diced onions, bell peppers, and celery to the skillet. Sauté until soft, about 5-7 minutes.
Stir in the minced garlic and cook for an additional minute until fragrant.
Add the shrimp to the pan and sauté until pink and opaque, about 3-5 minutes.
Remove shrimp from skillet and set aside. Add rice to the remaining mixture, stirring to combine.
Pour in the chicken broth and add the Cajun seasoning. Stir in the bay leaf.
Bring the mixture to a boil, then reduce heat to low, cover, and simmer for 18-20 minutes until the rice is tender.
Once cooked, remove from heat and let it sit covered for 5 minutes. Fluff with a fork.
Gently fold the cooked shrimp back into the rice mixture, and season with salt and pepper to taste.
Serve warm, garnished with chopped green onions or parsley if desired.