Heat a Dutch oven over medium heat and add 1 tablespoon of butter and 1 tablespoon of oil. Add sausage and saute until lightly browned, 2 to 3 minutes. Remove sausage from Dutch oven and set aside.
Add remaining butter and oil to Dutch oven along with onion, celery, and green pepper. Saute vegetables until soft, about 3 to 4 minutes. Add garlic and cook 1 more minute. Add remaining ingredients, except crawfish, reserved sausage, and green onions, and stir together well.
Bring to a boil, reduce heat to medium-low and cover pot. Cook about 15 minutes, until rice is cooked and liquid is absorbed.
Add in crawfish and sausage and cook an additional 2 to 3 minutes to warm the crawfish. Sprinkle green onions on top and serve with additional Tabasco sauce.