Preparation:

Mix yeast and sugar into water and let sit 2 minutes. Meanwhile, coat large skillet with nonstick spray and cook potatoes on medium. Combine flour, salt, and olive oil in mixing bowl (or food processor if it has a dough blade).  
Knead yeast/sugar/water mixture slowly into flour/salt/oil mixture until thoroughly mixed (or use ‘dough’ setting on food processor). If dough is sticky, add more flour in small amounts. Divide dough into three balls. (Note: Recipe makes extra dough.) Coat each ball with small amount of olive oil. Place two balls in individual plastic bag and put into refrigerator for future use.Add cooking spray to tops of potatoes and flip once bottoms begin to crisp.
Add sea salt to taste. Preheat oven to 400 degrees F. In a medium saucepan, melt butter on medium, and whisk in flour to make a roux.  
Once roux is formed, add evaporated milk and continue to whisk until mixture is smooth and begins to thicken. Add portabella mushrooms and pepper to taste, and cook on medium-low for approximately 2 minutes, stirring constantly (reduce heat and add additional milk if mixture becomes too thick). Turn off heat and set aside.  
In a large baking pan (roughly 17” x 12”) , apply generous amount of nonstick spray and press dough with fingers until dough covers most or all of pan. Spread portabella sauce across pizza. Add fried potatoes and cover with cheese. Bake for approximately 20 minutes, or until dough and cheese start to brown. Remove from oven and drizzle truffle-infused oil over top. Sprinkle sea salt to taste and serve.