Casônsèi from Val Camonica

Name: Casônsèi from Val Camonica
Ingredients: 2 3/4 cups all-purpose flour, plus extra for dusting; 3 eggs; 1 tablespoon olive oil; 1 pound 2 ounces potatoes, diced; 14 ounces Swiss chard, stalks removed; 3 tablespoons butter; 1 garlic clove, finely chopped; 1 sprig chopped fresh parsley; 1 leek, chopped; 7 ounces Italian sausage, skinned and chopped; 3/4 cups bread crumbs; Generous 1 cup grated Parmesan cheese; 1 egg, lightly beaten; Salt and pepper; 4 tablespoons butter, melted; 2/3 cup grated Parmesan cheese