Preheat the oven to 400 degrees F. In a large saute pan, over medium heat, add the oil. When the oil is hot, add the onions. Season with salt and pepper. Saute for 2 minutes. Add the peppers. Season with salt and pepper. Continue to saute for 3 minutes. Remove from the heat and set aside. In a large saute pan, over medium heat, add the sausage and render for 4 to 6 minutes. Remove and drain on paper towels. Divide the dough in half and roll into a 14-inch circle, about 1/2-inch thick. Press the dough into 2 greased 12-inch deep-dish pizza pans. Sprinkle each pizza with 6 ounces of the grated cheese. Spoon 1/2 of the onion and pepper mixture over each pizza. Sprinkle 1/2 of the sausage over the onion mixture on each pizza. Spread 1 cup of the tomato sauce over the top of each pizza. Sprinkle each pizza with 1 tablespoon of oregano. Bake the pizzas for 25 to 30 minutes or until golden brown. Remove the pizza from the oven and cut into individual servings.