Preheat oven to 450 degrees
Cook sausage in a medium skillet over medium-high heat for 5-6 minutes until browned and cooked through. Remove from pan and drain on a plate lined with a paper towel.
Rub each of two small cast iron skillets with ½ tsp garlic olive oil, being sure to coat bottom and sides. Divide the pizza dough between the two skillets. Press the dough to cover the bottom of the skillets.
In a small bowl, mix 2 tsp of garlic olive oil with the pesto.
Sprinkle two tablespoons of cheese on each pizza. Divide the pesto mixture evenly between the two pizzas, spreading over the cheese.
Top with mushrooms, sausage and the remaining cheese. Bake for 20 minutes, or until the crust turns lightly golden brown. Remove pizzas from oven and let cool for 5 minutes before slicing.