Not long ago, Myke Olsen worked as an accountant. Today, he bakes pizza on the sidewalk of Main Street in Mesa three nights a week, somehow managing to keep his long-fermented dough at the right temperature even in the arid heat. Olsen uses a pair of portable gas-fired grills that range from 700 to 800 degrees. His Thursday, Friday, and Saturday pop-ups sell a mere 20 to 60 pizzas a night. Crust puffs to airy edges on the rim, brown, black, and cratered. His crust has nuance and swagger, the complexity of great bread. Don't miss Olsen's marinara pie, or his potato pie with bacon and garlic cream.