In a large bowl beat together the eggs, flour, milk and salt. Gently mix in your favorite sausage or leftover meat, we used a garlic sausage. Or substitute a meatless alternative or omit for a vegetarian option. Once the skillet or pie plate in the oven is hot add the butter. Once it's melted remove the pan from the oven, swirl the butter around and then pour the dutch baby batter into the pan. Immediately place the pan in the oven.