For the pasta, place the flour, egg and egg yolks into a food processor and pulse until well combined and the mixture comes together as a dough. Place the dough in a bowl, cover with cling film and place in the fridge to rest for 30 minutes.
Cut the pasta dough in half and pass it through a pasta machine at its widest setting. Repeat this process, decreasing the roller setting down grade by grade with each pass until the dough is thin enough to pass through the spaghetti cutter.
Add the spaghetti cutter to the pasta machine and pass the pasta through the machine to make thin strips. Dust the pasta with a little semolina.
Repeat the process with the remaining dough, then place the spaghetti onto a plate and use immediately or refrigerate overnight.
For the tomato sauce, heat a frying pan over a medium-high heat and add the olive oil, tomatoes, garlic and chilli. Simmer for 30 minutes, or until the tomatoes have just started to break down.
Stir in the basil and season, to taste, with salt and freshly ground black pepper. Keep warm.
For the langoustine shell foam, heat the olive oil in a pan. Fry the shallot, garlic, tomato purée and star anise for 2-3 minutes, or until the shallots and garlic are softened.
Add the shells from the prawns and langoustines and stir. Add the brandy and white wine to the pan, scraping up any browned bits from the bottom of the pan to de-glaze. Stir in the fish stock and bring to the boil. Reduce the heat and simmer until the volume of the liquid has reduced by a third.
Remove from the heat and discard the star anise. Transfer the mixture to a food processor and blend until smooth. Pass through a sieve back into the pan. Blend with a hand blender until a foam develops, then set aside.
Heat a frying pan, add a little olive oil and fry the langoustine and prawn meat for a few minutes. Add to the tomato sauce.
For the pasta, in a large pan of salted boiling water cook the spaghetti until al dente.
To serve, stir the prawn sauce through the spaghetti. Transfer to serving dishes, spoon some foam over the top and sprinkle with basil cress.