Add peppers, onion, jalapeño, garlic and oil in a bowl. Toss with salt and set aside.
Heat oven to 500 F, put baking sheet on middle rack.
Stretch or roll dough until thin, about a 10-inch diameter. If sticking dust with flour.
Place dough on a parchment-lined baking sheet.
Sprinkle pizza with grated cheese, sliced fresh mozzarella, pepper, and onions. Arranges slices of sausage on pizza. Sprinkle pizza with chopped oregano.
Place pizza with the parchment onto the heated baking sheet. Bake for 5-7 minutes until dough is browned, sausage is cooked and pepper and onions are slightly blackened.
Remove pizza from oven, place on cutting board, and cut into slices. Serve immediately.