Grease a 10 x 7 or a 13 x 9 baking dish with oil or butter. Preheat oven to 400.

Peel and slice potatoes and onion. Take 1/2 of potatoes and place evenly into bottom of pan. Sprinkle with truffle salt and pepper and some fresh thyme. Top with 1/2 of the creme fraiche. Spread it on. Top with 1/2 of the truffle cheese. Drizzle with 1 T of truffle oil. Top with sliced onion.

Now take the rest of the potatoes and place evenly on top of the onion. Sprinkle with truffle salt and pepper and thyme. Top with the rest of the creme fraiche. Top with the rest of the truffle cheese. Drizzle with 1 T of truffle oil.

Place pan in oven for 30 minutes uncovered. Then reduce temperature to 350 for 30 more minutes. If potatoes start to brown too much, cover with foil. Check potatoes for doneness by sticking a knife into them. If knife inserts easily then potatoes should be cooked through.

Drizzle with last tablespoon of truffle oil before serving and a little more truffle salt. If you keep this covered and are worried that the mixture needs more moisture, pour on a little extra heavy cream. It will easily be absorbed by the potatoes.

Now have a glass of wine and celebrate!