Shallow fry gently, the chopped onion in a spoon of butter until soft. Stir in the curry powder and paprika, cook for further 1 minutes, splash in the stock and bring to the simmer. Pour in the cream, season with salt and pepper and reduce into a thick sauce. Meanwhile put the pasta to the boil in boiling salted water. Melt the remaining butter in a separate pan; toss in the shrimps with the garlic, take some of the pasta boiling water and pour over the shrimps. Drain the pasta and mix with shrimps’ sauce, simmer gently until glazed. Remove from heat, season with salt, pepper and cheese, finish with the spinach leaves. Serve the curry sauce with the cooked pasta.