To make filling, cook pumpkin in a steamer or microwave until soft. Place over a sieve to allow any excess liquid to drain. Mash pumpkin or puree with a stick blender and mix with amaretti biscuits, breadcrumbs, nutmeg and season with salt and pepper.

Place wonton wrappers on kitchen bench in a single layer. Place a spoonful of filling in the middle. Brush beaten egg around the edges and cover with another wonton wrapper. Press to seal edges and remove any air by gently pressing with a cupped hand. Cut with a ravioli cutter, or use a knife to trim the edges.

To cook ravioli, drop into a saucepan of simmering, lightly salted water and remove as soon as they float to the top, after 2-3 minutes. Place in a warmed bowl and continue until all the ravioli are cooked. Melt butter in a large pan and fry sage leaves and walnut pieces until fragrant and crisp. Place ravioli in pan and gently toss to coat. Squeeze over lemon juice and serve with freshly grated parmesan.