In a large pan, melt 3 Tbsp of butter over medium-low heat. When hot, add the bread, and toast for 4-5 minutes until golden. Once browned, flip the bread and melt 2-3 Tbsp more butter into the pan, moving the bread slightly to absorb the butter. Toast for an additional 4-5 minutes. Once done, transfer to a plate and set aside.

As the bread toasts, mix together the cream cheese, mustard, Camembert cheese, and salt and pepper to taste. Set aside.

In a medium skillet, heat bacon over medium-low. Cook for 7-9 minutes, allowing the fat to render. Add the garlic and rosemary— cook 2-3 minutes more; salt lightly. Finally, add the shrimp and season with salt and pepper; cook 2 minutes, or until just pink and firmed. Remove from the burner and allow the residual heat of the pan to finish cooking the shrimp. As it rests, spread the cheese onto the toasts. Top with the shrimp and bacon, a sprinkle of parsley, and a squeeze of lemon juice. Serve warm.