Cook the pasta until al dente according to the instructions on the packet.
Clean and chop the onions. Fry them in hot olive oil in a pan until they turn golden. Then drain the tuna and add it to the pan. Briefly heat the whole thing together. Now add the crème fraîche and let it melt. Then mix everything with the cream and bring to the boil. Finally, season with salt and pepper. If you like it a little hotter, you can add a little chilli as needed. Arrange on plates with the pasta and serve.
Tip: The sauce tastes great with any type of pasta.