A truly comforting dish with tender potatoes, sweet onions, and a rich blend of Gruyère and cheddar, baked to golden perfection.
# What You'll Need:
→ Vegetables
01 - 2.6 lbs floury potatoes, peeled and thinly sliced
02 - 2 medium onions, thinly sliced
03 - 2 cloves garlic, minced
→ Dairy
04 - 5 oz Gruyère cheese, grated
05 - 5 oz mature cheddar cheese, grated
06 - 1 1/4 cups double cream
07 - 3.5 tbsp unsalted butter
08 - scant 1/2 cup whole milk
→ Seasonings
09 - 1/2 tsp freshly grated nutmeg
10 - 1 tsp Dijon mustard
11 - Salt and freshly ground black pepper to taste
→ Topping
12 - 2 tbsp fresh chives, finely chopped
# How-To:
01 - Preheat oven to 375°F. Generously butter an 8-cup ovenproof pie or casserole dish.
02 - Melt butter in large saucepan over medium heat. Add onions and garlic, cook 6–8 minutes until soft and translucent but not browned. Remove from heat.
03 - Whisk together cream, milk, Dijon mustard, nutmeg, salt, and pepper in bowl until combined.
04 - Arrange half potato slices in prepared dish with slight overlap. Top with half onion mixture, then sprinkle with half Gruyère and cheddar.
05 - Repeat layering with remaining potatoes, onion mixture, and cheeses.
06 - Pour cream mixture evenly over layers. Press down gently with spatula to compact ingredients.
07 - Cover dish with foil. Bake 40 minutes until potatoes begin to soften.
08 - Remove foil and continue baking 20 minutes until golden brown and bubbling. Let rest 10 minutes before serving. Garnish with chives if desired.