Bring 6 quarts of water to boil in a large pot. Add 2 tablespoons salt and the potatoes. Cook until the potatoes are tender, about 8 minutes. Drain and reserve 1/2 cup cooking water. Set aside.
In a medium saute pan, heat 1/4 cup of the olive oil until hot but not smoking. Add the garlic and cook over medium heat, stirring often, until the garlic turns a light golden brown, about 2 minutes. Add the asparagus and the reserved potato water to the pan. Season, to taste, with salt and pepper. Turn the heat to high and bring the water to a boil. Return the heat to medium and cook, stirring occasionally, until the asparagus is tender, about 5 minutes.
Heat a saute pan over medium heat. Add the pancetta cubes and cook, over medium-low heat, until the fat from the meat is completely rendered, about 10 minutes. Once the pan has enough pancetta fat, add the cremini mushrooms and saute in the pancetta fat until golden brown, about 10 minutes.
Preheat the oven to 350 degrees F.
Using a few tablespoons of olive oil, grease a 12-inch round baking pan with 3 to 4-inch sides. Coat the pan with the bread crumbs, shaking off any excess crumbs. Set the dish aside.
Pass the potatoes through a food mill into a large bowl. Add 1/4 cup oil, eggs, cheese, mint, and season, to taste, with salt and pepper. Stir to combine well. Spoon 1/2 of the mashed potatoes into the prepared pan and, using a wooden spoon, smooth them evenly across the pan to form and even layer. Spoon the asparagus and then the mushrooms over the potatoes, using the spoon to smooth each into an even layer. Top the mushrooms with the remaining potatoes, using the spoon to spread them evenly. Bake until the edges are golden brown, about 35 to 40 minutes. Remove from the oven and serve either hot or at room temperature. Serve with Hee Hee Garnish.
Combine all ingredients and spoon on top of potato cake.
Recipe courtesy of Mario Batali