Peel and devein the prawns. Heat some olive oil in a pan and fry the peels in it for 2-3 minutes. Roughly dice the onion and a clove of garlic and add to the skins with the chilli, a few rosemary needles, a few sprigs of thyme, the bay leaf and 1 tablespoon of tomato paste and stir-fry until all the ingredients have taken on a nice color. Then deglaze with the white wine and vegetable stock and reduce by about half. Strain off the resulting stock and set aside.
Heat a little olive oil in the pan, add a whole, pressed garlic clove with peel and 2 - 3 sprigs of thyme. Season the prawns with salt and pepper and fry them on both sides for about 1 - 2 minutes (depending on size) until they get color. Keep warm.
Take the garlic clove and the thyme sprigs from the pan, loosen the roasting mixture with the stock, add the tomatoes, cream and saffron and reduce over medium heat until the sauce is nice and creamy.
In the meantime, cook the tagliatelle al dente according to the instructions on the packet.
Add the chopped parsley to the sauce, season with curry, salt and pepper and add the prawns to the sauce.
Drain the pasta and serve on plates with the sauce and a few prawns.