Barbecue Pork Pizza

Name: Barbecue Pork Pizza
Ingredients: 3 1/2 lb. boneless pork shoulder (Boston butt), trimmed and cut into 6 cubes; 1 medium-size yellow onion, trimmed, peeled, and quartered; 6 large garlic cloves; 1 Tbsp. kosher salt; 1 cup barbecue sauce, divided; 1 Tbsp. olive oil; 16 oz. fresh pizza dough, at room temperature; 8 oz. shredded low-moisture, part-skim mozzarella cheese (about 2 cups); 1/2 cup thinly sliced red onion (from 1 small onion); 1/3 cup drained, sliced pepperoncini peppers; Chopped fresh cilantro, for garnish