French Potato and Onion Gratin Recipe

A classic fall side dish, French Potato and Onion Gratin, combines potatoes and onions in a cheesy cream sauce. Perfect for family dinners or holiday gatherings.  

– 2 russet baking potatoes, washed and peeled – 1 medium onion – 1 tsp salt and fresh cracked black pepper to taste – 2 cups shredded sharp cheddar, divided – 1 cup heavy cream, divided – 3 Tbsp fresh marjoram, oregano, or thyme leaves, plus for for garnish – 2 Tbsp butter, cut in piece



Set oven to 350F Mandoline slice peeled potatoes into 1/8-inch pieces. Slice onions similarly. Quarter the onion slices to avoid stringy parts.

Step 1

Step 2

Combine onions, potato slices, 3/4 cup cream, fresh herbs, and 1 1/2 cups cheese in a large bowl. Mix well with clean hands. Season with cracked pepper and salt. 

Step 3

Separate potato pieces as much as possible. Put the mixture in an 11-12 inch gratin dish. Arrange potatoes equally. Dot butter.

Step 4

Mix the rest of the cheese and cream together. Put pieces of butter on top of the potatoes, and then cover them with the rest of the cheese and cream.

Step 5

Roast the potatoes for 90 minutes, loosely covered with foil, until golden and bubbling and easily pierced with a sharp knife. 

Step 6

Take off the paper for the last half hour of baking. Run it under the grill at the end to get more color.  

Also See

Easy Roasted Rainbow Vegetables Recipe