1 (16 ounce) package ground pork sausage
1/4 cup butter, or as needed
2 (12 ounce) packages English muffins, split
10 ounces shredded sharp Cheddar cheese, divided
1 (8 ounce) package shredded mozzarella cheese, divided
8 large eggs
1 1/2 cups sour cream
1 (4 ounce) can chopped green chilies, drained
1. Heat a large skillet over medium-high heat and stir in sausage. Cook and stir until sausage is crumbly, evenly browned, and no longer pink, about 10 minutes. Drain and discard any excess grease.
2. Lightly grease a 9×13-inch baking dish.
3. Spread butter on the inside of each English muffin half. Arrange buttered English muffins in the prepared baking dish; top with half the sausage, half the Cheddar cheese, and half the mozzarella cheese.
4. Whisk eggs, sour cream, and green chilies together in a large bowl; pour evenly over sausage and cheese layer. Top with remaining sausage, Cheddar cheese, and mozzarella cheese. Cover and chill for 8 hours.
5. Preheat oven to 350 degrees F (175 degrees C).
6. Bake strata in the preheated oven until lightly browned and set in the middle, about 35 minutes. Let stand for 10 minutes before serving.