Preheat the oven to 340 °F.

Remove the pork tenderloin from the refrigerator so it can come to room temperature. Season the meat with salt and pepper to taste.

Peel the potatoes and cut them into thin slices about 1/8 inch thick. Use a mandoline or a sharp potato knife so the slices are even.

Heat a saucepan and pour in the milk and cream. Add the crushed unpeeled garlic, the dried rosemary, the bay leaf and the dried thyme. Season the mixture with freshly ground pepper, a pinch of salt, and a pinch of ground nutmeg.

Warm the mixture over low heat and let the herbs infuse their flavor: it may get hot, but do not let it boil.

Melt a knob of butter and use a kitchen brush to grease the inside of a baking dish. Arrange the potato slices in the dish, overlapping like roof tiles, and build in layers until the dish is two-thirds full.

Strain the hot milk-and-cream mixture and pour it over the potato slices until they are just submerged.

Sprinkle a layer of grated Emmental cheese over the potatoes.

Place the dish in the oven and let the potato dish cook for about 30 minutes, until it has a golden-brown cheese crust. Check doneness by piercing the potato slices with a small knife.

Melt a knob of butter in a tall pan and sear the pork tenderloin for 2 minutes on both sides over medium heat, so the meat only picks up a little color.

Place the pork tenderloin in a small baking dish and slide it into the preheated oven. Check the meat after 7 minutes; leave it in the oven for a total of 10 to 12 minutes. It should feel firm when pressed.

Wrap the meat in aluminum foil and let it rest while the potatoes continue to cook.

Warm the sour cherries in a pan over medium heat. Reserve a little of the juice and mix it with the cornstarch.

Add the cornstarch mixture to the sour cherries and let it simmer briefly. Season to taste with pepper, salt, thyme, and rosemary.

Serve everything on a plate and enjoy your meal! Bon appétit!