Start cooking the pasta according to the instructions in the packet. While it's cooking prepare your sauce.
Chop the onion and garlic. Add oil to a pan and sauté the garlic and onion in the pan until they are soft.
Add the anchovies and keep mixing on a medium heat until they have dissolved into the oil and onion mixture.
Add the tomatoes and keep stirring once in a while until they start to soften. You can also close the pan with a lid and leave everything simmer for a little while. This way the tomatoes soften little quicker.
Remember to check on the pasta! You don't want it over done. Once it is al dente drain it and leave it to the side.
Once the tomatoes are soft in your pan, add the creme fraiche and mix it in.
Combine the pasta and the sauce. Add parsley, mix and sprinkle with parmesan.