How to make pizza without pizza sauce?
Focaccia dough stretched and rolled thin, painted with olive oil, sprinkled with fresh herbs and coarse salt then lanced about with a fork is a wonderful pizza with no need for any sauce or other toppings as a snack of side dish.  From there as a starting point you can start adding toppings, cheeses, even sauces to ones hearts content.  Herbs could be dried rather than fresh, but fresh basil or oregano are a good starting point.  I love a good sauce, but in no way is any sauce needed for a pizza.  If you want a sauce however, most anything that pairs with your toppings will work and there is no reason to skimp on creativity.  BBQ with chicken or shredded pork.  An Alfredo with shrimp or chicken.  A yogurt with fresh fruits for dessert.  There really are no rules.  Pizza is in my opinion defined by location and taste, not by some specific definition and is fully open to interpretation.  With a good base if needs no sauce.  With a lesser base, yes I want a sauce, but not to be limited to what some shop defined as appropriate.