Boil your water for your pasta, fettucine takes about 9 minutes to cook, cook according to package directions.
While your water is set to boil, start crisping your lardon/bacon in a saute pan. When it is crisp remove it from pan. Leave any visible fat in the pan.
Separate egg yolks from whites, leave in half shells to be served with pasta.
Add you creme fraiche' to the fat in the pan, allow to melt, stirring constantly, add salt and pepper to taste, add heavy cream, I used about 1/2 liter tonight.....it just depends on how much sauce you think you will use with dinner. Do not let this mixture boil much. You just want it to come to the point of boil and remove it. It will be somewhat thick at this point.
When you past is ready and your sauce is hot you are finished.
Serve with egg and shredded swiss cheese.