Ingredients:
4 medium Yukon Gold potatoes, thinly sliced (about 1/8″ thick)
2 medium leeks, white and light green parts only, thinly sliced and rinsed
1 1/2 cups Gruyère cheese, grated (or substitute Swiss)
1 cup heavy cream
2 tbsp unsalted butter, melted
1 tsp fresh thyme leaves (or 1/2 tsp dried)
1 tsp fresh rosemary, finely chopped (or 1/2 tsp dried)
2 cloves garlic, minced
Salt and freshly ground black pepper, to taste
Optional garnish: fresh parsley or chives
Instructions:
1. Preheat grill or oven to 400°F (200°C).
2. Prep foil packets: Tear off 4 large sheets of heavy-duty foil (about 12×18 inches). Spray or lightly brush each with melted butter.
3. Assemble the layers:
On each foil sheet, layer the sliced potatoes and leeks. Sprinkle each with Gruyère cheese, a few thyme and rosemary leaves, and a pinch of garlic. Season with salt and pepper.
4. Add cream and butter:
Drizzle 1/4 cup heavy cream over each packet. Finish with a little melted butter.
5. Seal the packets:
Fold the foil tightly around the mixture to create a sealed packet, crimping the edges well to prevent leaks.
6. Cook:
On the grill: Place packets on medium-high heat, close the lid, and cook for 30–35 minutes until potatoes are tender.
In the oven: Place packets on a baking sheet and bake for 35–40 minutes.
7. Serve:
Carefully open each packet (steam will be hot!). Garnish with chopped parsley or chives if desired, and serve straight from the foil or transfer to plates.
Tips:
Add crumbled cooked bacon or ham between layers for a heartier version.
If Gruyère is unavailable, sharp white cheddar or Emmental also work well.
For extra crispiness, broil the open packets for 2–3 minutes at the end.