Preheat your oven to (400°F) = (204°C). Wash the zucchini and slice them in half lengthwise. Scoop out some of the seeds and plant "meat" to make room for the toppings on the pizzas. A spoon or melon baller works great to remove the space you need for the toppings. Pat dry. Place them evenly on a cookie sheet with parchment paper. Set them aside. Grab a frying pan and fry the sausage until cooked through and crumbly. Drain the grease and set it aside. Chop the vegetables and set them aside. Spread the pizza sauce evenly on the zucchini halves. Sprinkle them with sausage, onions, bell pepper, and mushrooms. Top with shredded Mozarella cheese. Bake for 15-17 minutes or until the cheese on top is melted. Enjoy.