Taste

Mashed Potato Gratin

Ingredients

• 3 tablespoons butter, plus more for baking dish
• 1.4kg potatoes, peeled and chopped
• Coarse salt
• 3 large egg yolks
• 1 1/4 cups milk
• 1 1/2 cups coarsely grated Gruyere, Jarlsberg, or other Swiss cheese 

Method

1. Preheat oven to 180 degrees. Butter a shallow baking dish. In a large pot, cover potatoes with water by 2cm; add 1 tablespoon salt. Bring to a boil; reduce heat. Simmer until easily pierced with a paring knife, about 20 minutes. Drain. Wipe pan; return potatoes.
2. Add butter; mash with a potato masher until creamy. Cool slightly. Fold in egg yolks, milk, 1 1/4 cups cheese, and 2 teaspoons salt. Spread in prepared dish.
3. Top with remaining cheese. Bake until golden brown in spots, rotating dish halfway through, about 30 minutes.