Cut the fresh pasta sheet(s) into 36 circles using a pastry cutter.
Defrost the prawns, and chop them finely. Chop the chillies, garlic and parsley and mix with the double cream and the prawns. Season with salt and pepper.
Place a small amount of the filling in the middle of one of the pasta circles and brush around the filling with some egg yolk.
Take another pasta circle and place on top of the filling. Seal the edges of the ravioli making sure not to leave any pockets of air. Use a crinkled pastry cutter, trim off the edges.
Continue until you have 18 ravioli.
For the caramelised onion sauce:
Chop the onions and tarragon. Heat a saucepan, add the butter and melt. Add the onions, season with salt and pepper and cook slowly until the onions are soft and caramelised. Mix in the chopped tarragon with a splash of water.
Cook the ravioli for 3 minutes in salted boiling water. Drain and serve immediately with the onion sauce.
«The king prawns can be replaced with crayfish tails, and vary the flavour of the onion sauce by adding fresh thyme instead of tarragon.»