Ingredients for the gratin layers:
- 3-4 large russet (peeled) or Yukon gold potatoes, very thinly sliced
- 1-2 large apples (granny smith or fuji), very thinly sliced
- 3 cups Parmesan cheese
Ingredients for sauce:
- ¼ c butter, salted
- 1 large sweet onion, chopped
- 2 large apples (peeled, use the same as for the layers), chopped
- 1 T minced garlic
- 1 lemon halved
- 4 cups chicken stock or vegetable stock, chicken is preferred unless making it vegetarian
- 2 cups heavy cream
- Salt and pepper to taste
Cooking Directions for sauce:
- In a medium saucepot, on medium heat, melt butter. Once melted, add garlic, chopped onion, and apple. Once the onion and apple have softened, add chicken stock and the lemon halves.
- Bring to a simmer and reduce by ¼ the amount of liquid.
- Once reduced, add heavy cream, stirring constantly to not curdle the cream. Reduce this mixture by ½ the amount, the liquid should be thick.
- Remove the lemon halves and transfer the rest of the mixture into a blender or leave in the saucepot and you can use an immersion blender to blend the sauce until smooth.
- Adjust with salt and pepper as needed, set aside until the apples and onions have been assembled.
- Spray an 8x8 pan with nonstick spray, or you can use butter to run along the edges and bottom of the pan.
- Begin layering the potatoes and apples, beginning with potatoes on the bottom.
- Between each layer, sprinkle parmesan cheese and light salt and pepper.
- Continue layering until the pan is approximately ½ inch from the top.
- Pour the cream sauce over the layers, allowing it to settle into all the layers.
- The sauce should come just above the final layer. Finish with parmesan cheese.
Preheat oven to 375 degrees. Place baking dish on a ½ sheet pan or cookie sheet in case of overflow. Bake for 45 minutes. Take a small pairing knife once baked and poke the middle of the dish. There should be very little resistance. If still firm, bake for an additional 5 – 10 minutes, or until soft. Allow setting for 15 minutes before serving. This dish pairs excellently with roasted chicken or steak.