Crushed red pepper, for serving
1 red onion, thinly sliced into rounds
3 oz. sliced pepperoni (¾ cup)
12 oz. part-skim mozzarella cheese, shredded (about 3 cups)
½ tsp. kosher salt
½ tsp. dried oregano, plus more for serving
1 clove garlic, grated
2 tbsp. heavy cream
1 cup crushed tomatoes
1 recipe Master Pizza Dough
2 tbsp. olive oil