1. Preheat the oven to 175°C.
2. Grease the moulds of a cupcake tray with melted butter.
3. Brush squares of filo pastry with melted butter and carefully push into each mould.
4. Repeat with a further two squares of filo pastry until you have 10 pastry cases, each three layers thick.
5. Combine all the ingredients for the filling and carefully divide between the pastry cases.
6. Bake in the oven for 13-16 minutes until the tops are firm to the touch and golden brown.
7. Allow to cool then top each with crushed walnuts, grated Parmesan and half a slice of Parma ham.
Cook's tip: For bite size canapés, use smaller squares of fill party to line the moulds of a mini muffin pan. The filling mixture should make enough for 18-20 canapés.