Warm Onion Potato Gratin

By mamapig

Ingredients

• 1-1/2 lbs. Yukon gold potatoes, peeled, cut into 1/4" slices
• 3/4 lb. onions, thinly sliced
• 1 cup packed grated Gruyere cheese (about 4 oz.)
• 8 Tbs. packed freshly grated Parmesan cheese (about 2 oz.)
• 2/3 cup whipping cream

Preparation

Step 1

Preheat oven to 400°

Combine Yukon Gold potatoes and sliced onions in heavy large saucepan. Add enough water to cover. Bring water to boil. Reduce heat and simmer until potatoes are almost tender, about 3 minutes. Drain potato onion mixture well.

Arrange half of potato mixture in 11x7" glass baking dish.
Sprinkle with salt and pepper.
Sprinkle mixture with 1/3 cup Gruyere cheese, then 2 Tbs. Parmesan cheese.
Arrange remaining potato mixture atop cheeses. Pour cream over. Sprinkle with salt and pepper, then remaining 2/3 cup Gruyere cheese and 6 Tbs. Parmesan cheese.
(Can be prepared 8 hours ahead. Cover and refrigerate.)

Bake gratin uncovered until cream thickens, about 25 minutes. Remove from oven. Preheat broiler. Broil gratin until top is golden, about 2 minutes.