Scott Staples built his burger bona fides at Quinn’s, then turned an old Fremont auto garage into a casual burger joint. Here, all-natural patties might be topped with gruyere and two kinds of mushrooms, or watercress, blue cheese, and caramelized onions. Customers might be budget-conscious food geeks or the sort of families who try to avoid family-geared restaurants. Both camps love the covered patio.