Bring the double cream to boil on medium heat; add the saffron, set aside for 10 minutes (or as long you need to prepare the rest of the dish).
Heat 0,5 tbsp olive oil with 3 tbsp butter on medium heat, add the chopped shallots and fry stirring for 3 minutes till they are golden.
Add the chanterelles and fry for approx. 5 minutes on medium heat; transfer to a bowl.
Cook the pasta as per the packet instructions (keep a cup of pasta cooking water).
Heat the remaining 0.5 tbsp olive oil and 1 tbsp butter on medium heat, add the prawns and fry stirring for 2 minutes till they are cooked.
Combine the prawns with the chanterelles, and saffron cream; heat, season well, and add the cooked pasta. If the dish seems to be too dry, add some of the pasta water (if you are not counting calories, you can add some extra butter).