In a large cast iron or nonstick skillet, start browning breakfast sausage in butter over medium heat. Break sausage apart as it cooks to create small crumbles.
While sausage is cooking, wash asparagus. Snap woody ends off and discard. Chop remaining asparagus tips into smaller, bite size pieces and add to the pan with sausage. Sprinkle with salt and pepper.
In a small bowl, whisk eggs and cream together with more salt and pepper. Stir in half the grated cheese.
Once asparagus is tender to your liking, reduce heat to medium low and pour over the egg and cheese mixture. Gently stir the eggs in with the sausage and asparagus to coat everything evenly. Cook about 2 minutes on the stove until the eggs around the edges start to cook. Top with remaining cheese and transfer to hot oven and bake until completely set, about 12 minutes.
Once frittata is completely baked, cool 5-10 minutes before cutting and serving. Serve warm.