2. For Cajun butter, place a medium sized saucepan on medium flame, add salt and pepper flakes in it.
3. Add rosemary, no salt rub, ground pepper, and garlic.
4. Pour Worcestershire sauce, and give it a good stir. Remove from heat.
5. On cooker, place the saucepan with Cajun butter.
6. Pour a few spoons of Cajun butter on the griddle or pan.
7. Drop mushroom on the butter over griddle, and sauté.
8. Meanwhile, lay 2 bread slices on the grill. Flip, and toast bread on both sides.
9. Baste bread with butter sauce.
10. After 3 minutes add shrimp with mushroom. Mix well.
11. When bread is toasted move it from direct heat. Cover, with lid and cook until shrimps are done.
12. Cut bread slices into half.
13. In a bowl, arrange the bread slices. Top it with mushroom and shrimp mixture.
14. Pour remaining Cajun butter sauce all over the bread, and serve hot.