# The Ingredients You'll Need:
→ Infused Cream
01 - 2 cups heavy cream (480 ml)
02 - 1 piece dried kombu (4 inches)
→ Potatoes
03 - 2 lbs Yukon Gold potatoes, peeled and thinly sliced
→ Other
04 - 2 cloves garlic, halved
05 - 2 tbsp unsalted butter, softened (30 g)
06 - 1 tsp fine sea salt
07 - 1/2 tsp freshly ground black pepper
08 - 1 cup grated Gruyère cheese (100 g)
09 - 1/2 cup grated Parmesan cheese (50 g)
# Step-by-Step Instructions:
01 - Combine kombu and heavy cream in a small saucepan and warm over low heat until just below simmering. Remove from heat and steep for 15 minutes. Discard kombu.
02 - Rub cut garlic cloves inside a 2-quart gratin dish, then generously butter the dish.
03 - Set oven to 350°F (175°C).
04 - Arrange half the sliced potatoes in an overlapping layer at the bottom of the dish. Season with half the salt and pepper, then sprinkle with half the grated Gruyère.
05 - Place the remaining potatoes on top, season with the rest of the salt and pepper, then top with the remaining Gruyère and all the Parmesan cheese.
06 - Pour the kombu-infused cream evenly over the potato layers. Dot with the softened butter.
07 - Cover loosely with foil and bake for 45 minutes.
08 - Remove foil and bake an additional 15 minutes until golden, bubbling, and potatoes are tender.
09 - Allow to rest 10 minutes before serving to set.
