Mix butter flour and salt until the flour resembles peas, add water and mix until you have a rollable dough. Place on floured surface and roll out to 1/8 inch thick and in a circle.
Preheat the oven to 400 degrees F and place either a pizza stone or cookie sheet upside down in oven. Place dough on a board that you can slide it off from into the oven and have a little cornmeal under the dough to help make it slide better. Turn the edges of the dough in about 1/4 inch and crimp at intervals to make a nice ruffly edge to your pizza, it will get crusty. Cover the dough with the cheese and set aside.
Trim the asparagus and blanch it for 3 minutes in boiling water in a shallow pan. Remove from pan and quickly dip in cold water to stop cooking process. Pat dry with paper towels and place in a pinwheel fashion around pizza dough with the stems meeting in the center and making a mound, sprinkle with a little salt and pepper and slide into the oven on hot surface of pizza stone or cookie sheet and bake for about 25 minutes or until crust is golden brown.
Remove from oven and cut into serving size pieces. While pizza is baking slice mushrooms and place a small amount of olive oil in skillet and add shallots and garlic cook for about 3 or 4 minutes and add mushrooms. Cook about 5 minutes.
Add just about 1 tablespoon of balsamic vinegar and stir; remove from heat, Spoon a little on each slice of pizza and serve.
Serves 4 to 6.