Gluten-Free DIY Portobello Pizza

4 organic Portobello mushrooms
Pizza sauce
Shredded mozzarella cheese
Pizza Toppings (pepperoni, cooked sausage, sliced olives, sliced cherry tomatoes, feta cheese, diced red peppers, diced red onions)  

Remove stems from mushrooms. Place mushrooms gill-side down in a baking dish. Let bake about 15 minutes at 350°F uncovered. Remove mushrooms. Turn over and place 1-2 tbsp. sauce on each mushroom. Cover with cheese and then toppings. Return to oven and bake another 10 minutes. Cut each mushroom into quarters and serve.