Finely chop the bell peppers, onion, and celery. Mince the garlic cloves. If using frozen shrimp, ensure they are completely thawed.

In a large heavy-bottomed pot, heat oil over medium-high heat. Add the sliced Andouille sausage, cooking until browned and crispy, about 5–7 minutes.

Reduce heat to medium, stir in the onions, bell peppers, and celery. Sauté for about 5 minutes until softened, then add garlic and cook for an additional minute.

Stir in the long-grain rice and Cajun seasoning, toasting for 1–2 minutes until well-coated.

Pour in chicken broth, add bay leaves. Bring to a boil, then reduce heat to low, cover, and let simmer for 20 minutes.

Check the rice for tenderness after 20 minutes. Remove the pot from heat and take out the bay leaves.

Fold in the thawed shrimp, cover, and cook for an additional 5–7 minutes until shrimp are pink and opaque.

Gently fluff the rice with a fork, serve hot, and consider garnishing with chopped green onions.