Add all the ingredients listed under “meat crust” to a large mixing bowl and knead with your hands until well combined.
With your fingers, spread the meat evenly across the greased baking sheet taking care to form a little “crust” along the edge, for a more authentic look.
Remove the stems off the mini-peppers, cut them in half and remove the seeds, if any. Place the peppers in a broiler pan and drizzle them with a little bit of extra-virgin olive oil, then sprinkle lightly with salt and pepper.
Place both the crust and the mini peppers in the oven and bake for about 20 minutes, until the meat is browned and the peppers are nicely roasted.
Meanwhile, add the sliced onions and ghee to a heavy skillet (preferably cast iron ) set over medium heat. Cook, stirring often, until the onions turn a nice golden color, about 15 minutes. Add the sage, salt and pepper, stir well and set aside.
Remove the meat and peppers from the oven. If you find that the meat has released a fair amount of liquid while cooking, you’ll want to carefully drain that.
Spread the caramelized onions across the meat, followed by roasted bell peppers, crumbled goat cheese and chopped walnuts; return the meatza to the oven for an additional 15-20 minutes, until the crust gets nice and crispy and the cheese starts to turn golden.
Cut your meatza into 6 pieces, dribble with a little bit more extra-virgin olive oil and chopped fresh parsley.