Warm up the milk on a gentle heat and crumble in the Stilton. Stir until they melt together.
Mix the cornflour with a little cold water to form a paste, then mix into the milk and cheese. Stir on a low heat until thickened, seasoning generously with cracked black pepper.
In a small pan, fry the sage leaves in melted butter.
Cook the tortelloni for 2 minutes in salted boiling water. Drain and plate up, topping with your melted cheese sauce, chopped hazelnuts and crispy sage leaves.