Melt the butter in a large skillet over medium heat. Add the shallots, green peppers and mushrooms and cook until the veggies begin to soften, about 3 to 4 minutes.
Take the casing off the sausage and discard. Add the sausage to the pan and break it up with the spatula. Cook until done all the way through (no longer pink), about 5 to 6 minutes.
Roll out your pizza dough of choice (try my homemade recipe or follow the Simple Mills box instructions - I used 2 boxes) and top with a thin layer of pizza sauce, shredded mozzarella, and then the sausage mixture. Bake according to pizza dough directions, top with freshly grated parmesan cheese, slice and serve.