In a large heavy bottomed skillet, add 1 stick of butter and melt over medium high heat.
Add the garlic and grated onion and cook for 1 minute, stirring constantly.
Stir in the chopped rosemary and Cajun seasoning.
Then add remaining butter, Worcestershire sauce, lemon juice, and hot sauce. Cook and stir for another minute.
Add the shrimp and cook for 2-3 minutes on each side or until shrimp are pink and opaque.
Season to taste with salt and pepper.
Remove skillet from heat and pour the shrimp into a bowl.
Ladle the sauce over the top.
Serve with hot out of the oven French bread for dipping and garnish with parsley and lemon wedges.