First, prepare the toppings you'll be adding to your meal. Below there are two kinds of olives, two different peppers, onions and diced bacon bits. Yes, REAL bacon. Not shown are the sauce and mozzarella cheese.
Of course, you'll need a base for your "pie". On your baking sheet, lay out a matrix of mushroom caps from which you have carefully removed the stems. Save the stems for use in another dish! These happen to be Cremini mushrooms about 2" across, but any size will work, and the more alike in size they are the better. White mushrooms will also work fine this way.
Fill each mushroom cap with a treasure trove of the diced bacon, Cant have too much, and it makes sure every bite has some great bacon taste.
Mozzarella cheese time. No need to be stingy, as whatever melts off is delicious in it's own right. You'll see later.
Now, layer on your toppings. I tried to keep them fairly even, but oh well. If you get them too close to the edges, they will just slide off with the cheese.
Into the oven at 400° to finish. You'll want to leave it in there until the veggies are done and the cheese starts to brown around the edged, as shown below. After you serve up the mushroom pizzas, that crispy-edged cheese is a real guilty pleasure to snack on!
Here you go, plated and reaty to devour. Note: These are a lot more filling than you might think, I only ate 4 of them. Hope you give this a try, and see how you like this way low carb version of your favorite pizza!