This is a rare treat here, but it is so good you will find any excuse to make this one yourself. It seems complicated and there are a few steps, but once prep is done and you're ready to assemble, it is really a breeze. You can save some time by using jar Alfredo sauce instead of making it. I usually kick out prep work here and there while I'm cleaning and doing chores.
Gluten Free Pizza Crust
In a large bowl, mix together your flour, baking powder, sugar, and yeast. Stir to combine well. Start adding in your water, beginning with only half. Stir and add in more as needed until it forms a wet ball. Rub with a bit of olive oil and leave it to rest for an hour or more, covered.
Slice the steak, onions and mushrooms and place in a large bowl or ziplock bag. Mix together your marinade and place in the fridge from 2 - 8 hours. When you are ready to prepare the pizza, place in a large skillet and on medium heat, cook until the meat is done and onions are softened.
Mozzarella or Provolone Cheese
Melt the butter, stir in your cream and then slowly add in the parmesan cheese and the feta. Keep stirring until cheeses are melted and everything is combined well. Add in your arrowroot and bring up to a boil, watching carefully so it doesn't burn. It will thicken into a nice semi thick sauce.
Using an oiled pizza pan, spread your dough out to form your pizza crust. Spread on the Alfredo sauce, aiming to get it evenly distributed. On top of that add your steak, onion, mushroom mix and then top with cheese. Bake in a 400 degree oven for 30 minutes or until cheese melts and begins to brown.