Spinach and Artichoke Football Empanadas

Name: Spinach and Artichoke Football Empanadas
Ingredients: 8 ounces cream cheese, at room temperature; 1/2 cup sour cream; 1/2 cup mayonnaise; 2 garlic cloves, minced; 1 cup shredded Gruyere; 1 cup shredded mozzarella; 1/2 cup shredded Parmesan; 10 ounces frozen chopped spinach, thawed and squeezed dry; One 14-ounce can artichoke hearts, chopped; Kosher salt and freshly ground black pepper; Two 14-ounce packages empanada discs, thawed; 1 large egg beaten with 1 tablespoon water