Cook the spinach according to package directions; drain well.
Sprinkle the cheddar cheese in the bottom of a buttered 13 x 9 x 2 inch baking dish; spread the spinach evenly over the cheese.
Cook the sausage in a skillet over medium heat until browned, stirring to crumble the meat; drain and sprinkle over the spinach.
Saute mushrooms and green onions in butter in a large skillet until tender. Sprinkle the sauteed veggies over the sausage.
Combine the eggs and cream, beating with a wire whisk until blended. Pour the egg mixture over the vegetable mixture. Top evenly with Swiss cheese; sprinkle with paprika. Bake, uncovered, at 350 degrees for 40 to 45 minutes or until set.