Gruyere Apple Idaho Potato Au Gratin with Fresh Marjoram
A luxurious twist on classic potato gratin featuring layers of Idaho russet potatoes and tart Granny Smith apples bound in rich heavy cream and melted Gruyere cheese. Fresh marjoram, garlic, and shallots add aromatic depth while nutmeg provides warmth. The apples bring subtle sweetness that balances the sharp cheese, creating an elegant side dish perfect for holiday gatherings or special dinners. This generous casserole serves a crowd and develops a beautiful golden crust while remaining creamy within.
Ingredients
- 8 large Idaho Russet potatoes, peeled and thinly sliced
- 4 Granny Smith apples, peeled, cored and thinly sliced
- 6 cloves garlic, peeled and chopped
- 8 cloves garlic, peeled and chopped(optional)
- 4 shallots, peeled and chopped
- 6 shallots, peeled and chopped(optional)
- 1 tablespoon fresh marjoram leaves, choppedfresh thyme1:1herb swap
different herb profile
- 2 tablespoons fresh marjoram leaves, chopped(optional)fresh thyme1:1herb swap
different herb profile
- 1 ½ pounds Gruyere cheese, grated
- 3 pints heavy cream
- salt
- white pepper
- nutmeg
Instructions
- 1
Peel and thinly slice potatoes
- 2
Peel, core and thinly slice apples
- 3
Peel and chop garlic and shallots
- 4
Chop fresh marjoram leaves
- 5
Grate Gruyere cheese
- 6
In large casserole dish, place single overlapping layer of potatoes then apples
- 7
Sprinkle lightly with salt, pepper, nutmeg, marjoram, garlic, shallots and cheese
- 8
Continue layering process until casserole is full with final layer of potatoes and cheese on top
- 9
Slowly pour heavy cream over dish, letting cream fill and come up over final layer
- 10
Press down gently on top potatoes to ensure final layer is submerged without being soupy
- 11
Cover with foil and bake at 375 degrees for 45 minutes or until potatoes are fork tender
- 12
Uncover and bake additional 25 to 30 minutes until top is golden brown
Tips
Use a mandoline or sharp knife to ensure uniform thin slices for even cooking throughout the gratin.
Press gently on the final layer to help cream penetrate between layers without making the dish soupy.
Let rest 10-15 minutes before serving to allow layers to set and make slicing easier.
Good to Know
Refrigerate leftovers up to 3 days. Cover tightly to prevent drying.
Assemble completely up to 1 day ahead, cover and refrigerate. Add 15-20 minutes to baking time if cold.
Serve hot as elegant side dish. Let rest 10-15 minutes before slicing for cleaner portions.
Common Mistakes
Slice potatoes uniformly to avoid uneven cooking with some pieces overdone and others undercooked.
Don't skip pressing the final layer to ensure cream distribution and prevent dry spots.
Substitutions
FAQ
Can I make this dairy-free?
Substitute coconut cream for heavy cream and use dairy-free cheese, though texture and flavor will differ significantly from traditional gratin.
What if I don't have marjoram?
Fresh thyme, rosemary, or sage work well as substitutes. Use slightly less as these herbs can be more potent than marjoram.
How long will leftovers keep?
Properly stored in refrigerator, leftovers keep 3-4 days. Reheat covered in 350F oven until heated through, about 20-25 minutes.