5 Servings (or 3 super delicious servings)
- 1 1/2 pounds medium Yukon Gold potatoes
- 1 1/2 pounds medium red-skinned sweet potatoes (yams)
- 2 cups heavy whipping cream
- 1/4 cup butter
- 2 cloves garlic, minced
- 1 tablespoon minced fresh parsley
- 1 tablespoon minced fresh sage
- 1 tablespoon minced fresh rosemary
- 1 tablespoon minced fresh thyme
- 1 1/2 teaspoons fine sea salt
- 3/4 teaspoon freshly ground black pepper
- 1 1/4 cups (packed) coarsely grated Gruyère cheese (about 5 ounces)
- Fill a large bowl with cold water
- Peel and cut potatoes into 1/8-inch-thick rounds and place in bowl with water
- Combine cream, butter, and garlic in a medium saucepan, and bring to a simmer
- Remove from heat
- Mix all herbs in a small bowl
- Mix sea salt and black pepper in another small bowl
- Butter a 13x9x2-inch glass baking dish
- Drain potatoes, then pat dry with kitchen towels
- Place half of the potatoes to the baking dish, spreading evenly
- Sprinkle half of the salt/pepper mixture, then half of herb mixture over the potatoes
- Sprinkle half of the cheese
- Create a second layer of potatoes and sprinkle with cheese, salt/pepper, and herbs
- Finally, pour the cream mixture over everything, patting lightly to submerge the potatoes. The potatoes won't be completely submerged, this is fine.
This can be made up to 6 hours ahead of time. Cover with plastic wrap and chill.
- Preheat oven to 400°F
- Cover the dish tightly with foil, and bake for 30 minutes.
- Uncover, and bake until top is golden and most of liquid is absorbed, about 25 more minutes
- Let stand 10 minutes before serving
- Whatever you do, do not try to substitute half-and-half for the cream to make a low-fat version. We tried this once, and the milk curdled when it was baking. It ended up tasting fine, but the milk was completely separated.