Step 1
Stir potatoes sour cream cream cheese 1 tablespoon butter egg yolk 1/2 teaspoon salt and 1/2 teaspoon black pepper together in a bowl until smooth.
Step 2
Heat olive oil in a cast iron skillet or nonstick pan over medium-high heat. Add ground lamb reduce heat to medium and cook stirring frequently until browned and crumbly 4 to 5 minutes. Pour off excess grease and season lamb with salt and black pepper to taste.
Step 3
Stir tomatoes with juice onion and carrot into ground lamb; simmer until vegetables are tender 5 to 10 minutes. Add peas reduce heat to low and cook stirring frequently until peas are warmed 2 to 3 minutes.
Step 4
Heat beer in a saucepan over medium heat; add beef bouillon. Cook and stir beer mixture until bouillon is dissolved about 5 minutes.
Step 5
Heat remaining 1 tablespoon butter in a separate pan over medium-low heat until sizzling. Whisk flour into butter until thick and paste-like about 1 minute. Stir beer mixture and Worcestershire sauce into flour mixture until gravy is smooth and thickened 2 to 3 minutes. Stir gravy into lamb mixture and simmer until mixture is thickened at least 5 minutes.
Step 6
Set oven rack about 6 inches from the heat source and preheat the oven's broiler. Grease a 9x12-inch baking dish.
Step 7
Pour lamb mixture into the prepared baking dish. Carefully spoon mashed potatoes over lamb mixture covering like a crust. Sprinkle Cheddar cheese parsley and paprika over mashed potatoes.
Step 8
Broil in the preheated oven until crust is browned and cheese is melted 4 to 5 minutes. Cool for about 5 minutes before serving.