If you serve our étouffée and have leftovers, slather it on top of grilled 'dogs.
Coat cold cooking grate of grill with cooking spray, and place on grill. Preheat grill to medium (350°F to 450°F). Brush hot dogs with Creole mustard. Split hot dog buns (if necessary), and brush inside with melted butter. Place hot dogs on cooking grate, and grill, turning occasionally, until slightly charred, 3 to 4 minutes. Transfer hot dogs to side of grate, away from heat, and place buns, buttered side down, over heat. Grill buns until golden brown, about 30 seconds.
Heat Crawfish Étouffée in a saucepan over medium-low just until warm. Place hot dogs in buns, and spoon 1/4 cup étouffée over each hot dog. If desired, top with fresh jalapeño slices, diced red onion, and diced plum tomato.