1. preheat oven to 350 degrees f. 2. Slice the french bread loaf in half lengthwise. scoop out some of the bread to make room for the filling, if desired. set onto a baking sheet. 3. Melt the butter in a large pan over medium heat. add the onion, celery, and bell pepper. cook for 5 minutes to soften. 4. Add the garlic and cook 1 minute. 5. Add the crawfish tails and cajun seasoning. cook for 2-3 minutes, stirring a bit. 6. Stir in the cream cheese until melted through and incorporated, about 2 minutes. 7. Transfer the pan ingredients to a mixing bowl. stir in the mayo, mustard, and shredded cheeses. mix until well combined. 8. Spread the cheese mixture over the pieces of french bread and bake for 12 minutes. 9. Increase oven heat to “broil” then broil the crawfish bread until the bread is toasty and the topping is browned and bubbly. 10. Remove from heat, cool enough to slice, then serve