Prepare filling: Heat a large skillet over medium heat. Add the bacon and cook, stirring occasionally until browned and almost crisp, about 7 to 8 minutes. With a slotted spoon, transfer the bacon to a plate; set aside. Add the oil to the drippings in the skillet and put over medium heat. Add the onions and 1/2 teaspoon of salt, and cook, stirring occasionally, until the onions are very soft and just beginning to brown, about 10 minutes. Sprinkle in the sugar, and cook, stirring occasionally, until the onions begin to caramelize, about 3 minutes. Stir in the beef and cook, stirring occasionally, over medium-high heat, until the beef begins to brown, about 7 minutes. Add the carrots, peas, and garlic and cook, stirring, until the vegetables begin to soften, about 5 minutes. Stir in the tomato paste and flour and cook, stirring, until well blended, about 2 minutes. Add the beer, bring to a boil and boil for 3 minutes. Cook, stirring with a wooden spoon, and scraping up the browned bits from the bottom of the pan, about 2 minutes Add the cooked bacon, the broth, rosemary, 1/2 teaspoon of salt, and the pepper, and bring to a boil. Reduce the heat and simmer, uncovered, until the sauce thickens, about 15 minutes.
Spoon the meat mixture into the prepared baking dish. Spread the potato topping evenly over the beef mixture. Bake until the filling is hot, the topping is lightly browned and the edges are bubbly, about 35 minutes. Remove from the oven and sprinkle with the cheese. Return to the oven and bake for 10 more minutes. Let rest out of the oven for 10 minutes before serving. Sprinkle with parsley and serve.
Preheat oven to 350 degrees F. In a large mixing bowl beat shortening with an electric mixer on medium to high speed for 30 seconds. Gradually add sugar, about 1/4 cup at a time, beating on medium speed until light and fluffy. Beat in vanilla. Add egg whites, one at a time, beating well after each addition. Alternately add flour mixture and buttermilk mixture to shortening mixture, beating on low speed after each addition just until mixture is combined.
Spoon batter into prepared muffin cups, filling each about two-thirds full. Use the back of a spoon to smooth out batter in cups.
Bake for 15 to 18 minutes or until tops spring back when lightly touched. Cool cupcakes in muffin cups on wire racks for 5 minutes. Remove cupcakes from muffin cups. Cool completely on wire racks.
Divide White Chocolate Frosting between two bowls. Tint one portion with green food coloring. Spoon each frosting into a pastry bag fitted with a large star tip. Pipe white and green frostings onto tops of cupcakes to resemble four-leaf clovers. Makes 20 to 22 (2-1/2 inch) cupcakes!
Place white baking chocolate in a large mixing bowl; set aside. In a small saucepan heat whipping cream just until simmering. Pour over white baking chocolate; let stand, without stirring, for 5 minutes. Stir until smooth; let stand for 15 minutes. Gradually beat butter into melted white chocolate mixture with an electric mixer on medium to high speed, beating until combined. Gradually beat in powdered sugar until frosting reaches piping or spreading consistency. Makes 3-1/2 cups.