Instructions

• Preheat your oven to 375°F. Meanwhile, grab a glass casserole dish and butter it up with that tablespoon of unsalted butter. Get it nice and slick so potatoes don’t stick.
• Now, layer half the sliced potatoes at the bottom, making sure they’re kinda neat but you don’t gotta be perfect. Sprinkle half the minced garlic, salt, pepper, and nutmeg over the potatoes to spread that flavor love.
• Sprinkle half the grated Gruyère cheese over that first layer. Then repeat with the rest of your potatoes and seasonings, finishing it all off with the last of the cheese on top.
• In a bowl, whisk together heavy cream, whole milk, and Dijon mustard until it’s all smooth and blended. Pour this creamy mixture evenly over the potatoes. The cream kinda slips between layers making everything lush and moist.
• Cover the dish tightly with aluminum foil. That foil’s key to keeping heat and steam trapped when it goes in the oven. Bake covered for 30 minutes, then take off the foil and bake another 15 minutes to get that golden bubbly top you wanna see.
• When you pressure cook, you gotta keep an eye on that sealing ring to make sure it’s snug before you start. Use a broth depth of about an inch with water in your cooker to create the steam, not too much or potatoes get soggy.
• After cooking, do a quick release to get the pressure down fast so potatoes don’t keep cooking. Then let them sit a bit before scooping out those creamy layers. The whole thing works real good because that steam gently cooks potatoes just right.