Melt butter in a Dutch oven or large heavy pot over medium heat; add onion, green pepper, celery and garlic and cook until soft, about 5 minutes. Add salt and TABASCO® Sauce; cook, uncovered, over medium-low heat for 30 minutes, stirring occasionally.
Add crawfish tails, lemon juice and parsley. Cook another 10 to 15 minutes. Just before serving, add green onion. For best flavor, prepare dish the day before. Remove from refrigerator an hour before serving and reheat just until hot to avoid overcooking crawfish. Serve over rice.
Makes 6 to 8 servings.