Preheat the oven to 425°F on convection mode (or 450°F on regular mode) with the rack in the middle position, and place a large sheet of parchment on a clean, flat surface.
Spread the bulk sausage on the parchment, and use your hands to form the meat into a rectangle.
Place another piece of parchment on top of your sausage rectangle, and use your hands to evenly press down on the sausage between the two sheets of parchment paper. Then, use a rolling pin to uniformly flatten the sausage until it’s about ¼-inch thick, making sure it’s not too wide or long to fit on a half-sheet (18-inch x 13-inch) rimmed baking pan.
Peel off the top layer of parchment and transfer the flattened crust (with the sheet of parchment underneath) to a rimmed baking sheet.
Pop the baking sheet in the hot oven and bake until cooked through, about 10 minutes, rotating the tray around at the halfway point. The crust should be cooked through with some browning at the edges. Remove the pan from the oven.
At this point, you may notice a lot of accumulated sausage juice. Blot the crust well with paper towels. Then, carefully transfer the crust to a clean piece of parchment. Discard the old parchment paper, and wipe away any spilled meat juices from the rimmed baking sheet. Transfer the meat crust (with the parchment) back onto the baking sheet.
Now, it’s time to go crazy with the toppings: Slather a layer of marinara sauce on the meatza crust, and add your favorite toppings. Me? I like thinly sliced mushrooms, bell peppers, red onion slices, and olives. Add cheese if desired. I prefer dairy-free cheese or goat cheese (because I don’t do well with cow’s milk cheeses), so I’ll sometimes dollop on some chevre or almond milk ricotta.
Return the meatza to the oven, and bake for 5-10 more minutes or until the toppings are browned.
Take it out of the oven and let the meatza rest for 5 minutes. Last but not least: Slice and eat!
No rolling pin? No problem! Use a metal water bottle or the bottom of a large, flat-bottomed skillet.