Start with the pasta: prepare it as in Basics up to the asterisk mark, wrap and refrigerate it. Then deal with the spinach: soften the onions in the butter, add the spinach, chilli powder and seasoning to taste, cook for 3 minutes, drain it thoroughly and allow it to cool. Put the mixture into a food-processor, add the cheese and one egg-yolk and process it very briefly. Leave to cool.

Now make the sauce: peel the prawns and reserve them. Put together the heads, shells, tomato puree and the fish stock in a saucepan; bring it to the boil and reduce it by half. Using a potato-masher, smash up all the prawn shells so as to release the maximum flavour, then pass the stock through a sieve. Return the stock to the pan, add the cream and simmer for a couple of minutes. Add the peeled prawns and bring the sauce back to the boil for a minute then liquidise it and sieve it again. Finally return it once more to the pan, add the sherry and warm it through, taking care that it doesn't boil. Set it aside until you are ready to eat.

To make the tortellini, roll out the pasta (again, refer to Basics) and cut it into rounds on a floured surface. Brush the edges with beaten egg-yolk and put half a teaspoon of the spinach mixture in the middle. Fold each into a half moon, bring up the points and twist them together, twice.

Just before you want to eat, bake the fish, covered with foil, on a buttered dish for 3 to 4 minutes. Gently warm the sauce and bring a large pan of salted water to the boil. Cook the pasta for 2 minutes and drain it. To serve this dish, pour some sauce onto each plate then some tortellini, and top it all with the fish.

Graciously acknowledge the applause.