Preheat oven to 350 F.
Cut off the ends of the zucchini (6 medium size), then cut them in half lengthwise. Scoop out most of the flesh, leaving about 1/4 inch thick wall -- I do this with a spoon.
Drizzle zucchinis with olive oil (1 tablespoon), and place them on a baking sheet, cut side up.
Bake zucchinis in preheated oven for 15-25 minutes, or until they're tender to your liking. Use a fork to check doneness.
Meanwhile, cook Italian sausage (1 Lb ) in a large skillet over medium-high heat. Break the sausage into small pieces with the back of your spoon as it cooks.
Once cooked, remove sausage to a paper towel-lined plate to absorb excess grease.
Remove zucchini from oven, and bring oven to a broil.
Dab any accumulated water/oil from the center of the cooked zucchinis.
Add low carb pizza sauce (3/4 cup) to the zucchinis, followed by the sausage, shredded mozzarella cheese (2 cups), sliced onions (1/2 cup), sliced bell peppers (1/2 cup), sliced mushrooms (1/2 cup) and black olives (1/4 cup).
Bake until the cheese is golden brown and melted -- items will burn easily at this temp, so keep a close eye. I bake mine for 3-5 minutes.
Cover with fresh herbs, and allow pizzas to cool slightly before serving. Enjoy!