Preheat Oven: Preheat the oven to 400°F.
Brown Sausage: In a skillet, brown a pound of sausage.
Prepare Vegetables: Dice red pepper, onion, and mushrooms. Add them to the skillet with the sausage.
Add Garlic: Add minced garlic to the skillet and sauté with the sausage and veggies.
Prepare Batter: In a separate bowl, mix 1 and 1/3 cups of milk, 3 eggs, 3/4 cup of Bisquick, 3/4 teaspoon of sage, and 1/4 teaspoon of pepper. Whisk until smooth.
Combine Cheese: Mix in 2 cups of grated Monterey Jack cheese into the meat and veggie mixture in the skillet. Save about 1/2 cup of cheese for garnish.
Assemble: Pour the skillet mixture into a greased deep-dish pie plate. Pour the batter from the mixing bowl on top.
Bake: Bake in the preheated oven for 20 to 25 minutes.
Garnish: Sprinkle the remaining 1/2 cup of cheese on top and bake for an additional 1 to 2 minutes, just until the cheese is melty.
Cool and Serve: Allow the pie to cool for a few minutes before serving.
