Proof yeast untill bubbles form on bowl (about 10 minutes) add half the flour a nd stir until you arm falls off. Add the rest of the flour and 1 teaspoon of s alt one cup at a time, kneading until it no longer sticks to your hands. Cover in a floured bowl and let rise until almost doubled in bulk (about 1 hour in a warm kitchen).
Preheat Oven to 450 degrees, put pizza stone in. Heat stock in skillet, add garlic and potato: saute until potato is translu cent (but still crisp) and garlic is brown, about 6 minutes. Add beans and red pepper flakes: cook 1 minute. Roll out pizza dough good and thin on a cutting board or device used for del ivery to oven, liberally sprinkle with polenta or corn meal. Spread with musta rd, arrange potato mixture on top, sprinkle with cheese if desired. Put quickly in oven, bake untill crust is brown and vegetables are hot, abou t 8-10 minutes. Cut and serve.