Plug in pie maker. Cut tortillas using the tool provided. Set aside.
Fry sausage according to package directions. Remove from pan and add mushrooms. Cook over medium heat until browned, scoot to the side of the pan, and add spinach. Cook, stirring frequently, until wilted. Lightly salt and pepper the vegetables. Remove from pan. Chop the sausage up and mix in with the spinach/mushroom mixture.
Mix three eggs with milk and salt well.
Microwave tortillas for 20-30 seconds to soften. Press tortillas into pie maker using tool provided. Add a heaping tablespoon of filling, and fill remaining room with egg mixture. Sprinkle with cheddar cheese, and if desired top with top tortilla.
Close lid and cook 7-10 minutes. Check mid-way through. If the edges are getting overly browned, prop open lid for remaining time. Cook until centers are set.