2 medium onions
3-4 lbs yellow potatoes
½ lb Vivace
1 cup heavy cream
2-3 Tbsp Butter
Salt & pepper
Parsley, rosemary or other herbs for garnish (optional)
1. Preheat the oven to 375 F.
2. Slice onions thinly and saute in 1-2 Tbsp butter until golden brown.
3. Grease the bottom and sides of a 9 x 13 baking pan with butter. Spread onions across the bottom.
4. Slice potatoes very thinly with a knife or mandoline. Season the slices with salt and pepper and toss lightly.
5. Grate the Vivace with the large holes on a cheese grater to yield approximately 2 cups of grated cheese.
6. Spread 1/3 of the potatoes on top of the onions, then top with 1/3 of the cheese. Repeat two more times, ending with a layer of cheese.
7. Pour the heavy cream over the top of the entire casserole.
8. Bake covered with aluminum foil for 30 minutes, then remove the foil and bake for another 15-30 minutes. Gratin is done when casserole is bubbling, cheese is golden brown on top, and potatoes are tender when poked with a paring knife.
9. Let sit for 10 minutes before serving. Top with parsley or other garnish if desired.