Spanish Potatoes au Gratin (Patatas Gratinadas)

Spanish Potatoes Au Gratin (Patatas Gratinadas) in a baking dish

The Spruce / Wanda Abraham

Prep: 10 mins
Cook: 45 mins
Total: 55 mins
Servings: 6 servings
Nutrition Facts (per serving)
426 Calories
25g Fat
30g Carbs
20g Protein
Show Full Nutrition Label Hide Full Nutrition Label
Nutrition Facts
Servings: 6
Amount per serving
Calories 426
% Daily Value*
Total Fat 25g 32%
Saturated Fat 12g 62%
Cholesterol 112mg 37%
Sodium 384mg 17%
Total Carbohydrate 30g 11%
Dietary Fiber 3g 10%
Total Sugars 6g
Protein 20g
Vitamin C 12mg 61%
Calcium 439mg 34%
Iron 2mg 13%
Potassium 793mg 17%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

The north of Spain is famous for its variety of creamy cheeses, and many of them are sheep's milk cheese. Local dishes feature these cheeses in a variety of ways, and one that will quickly become a favorite is this delicious, cheesy Spanish potatoes au gratin (patatas gratinadas). This potato and cheese recipe is especially typical in the region Aragon, in northeastern Spain. It's usually served on the side with a hearty meat dish, though sometimes is served on its own as an appetizer or tapa.

This Spanish potatoes au gratin is easy to prepare and uses ingredients that are probably already in your pantry—potatoes, eggs, milk, cheese, and bacon or pork belly (pancetta). Moist, not runny, this dish has a solid consistency—a bit like a layered Spanish potato omelet with bacon.

Note: This recipe calls for Manchego cheese (sheep's milk cheese). If sheep cheese is unavailable, use another sharp cheese such as aged Monterey Jack.


  • 4 medium to large potatoes

  • 1 large onion

  • 2 slices bacon, pork belly, or Spanish pancetta

  • 3 tablespoons Spanish extra-virgin olive oil

  • 2 large eggs

  • 1 to 1 1/2 cups whole milk

  • Salt, to taste

  • 1 cup grated cured sheep's milk cheese, such as manchego cheese, for topping

  • 1 sprig fresh thyme, for garnish, optional

Steps to Make It

  1. Gather the ingredients.

    Spanish Potatoes Au Gratin (Patatas Gratinadas) ingredients

    The Spruce / Wanda Abraham

  2. Preheat the oven to 350 F. Peel and cut the potatoes into thin slices (1/8-inch thick). Peel and thinly slice the onion.

    Sliced potatoes and onions on plates

    The Spruce / Wanda Abraham

  3. Cut the bacon or pancetta lengthwise in strips and lightly fry them in a medium-high pan.

    Bacon strips cooking in a pan

    The Spruce / Wanda Abraham

  4. Remove the bits with a slotted spoon and allow to drain on a paper towel.

    Cooked bacon strips on a paper towel lined plate

    The Spruce / Wanda Abraham

  5. Oil the bottom and sides of a 9 x 12-inch glass baking dish. Place a layer of potatoes on the bottom. Lay the julienned onions and a couple of strips of bacon or pancetta on top to create another layer.

    Potatoes, onions and bacon in a baking dish

    The Spruce / Wanda Abraham

  6. Repeat this process until all potatoes, onions, and bacon has been used.

    Layers of potatoes, onions and bacon in a baking dish

    The Spruce / Wanda Abraham

  7. Beat the eggs and milk together, and pour over the potato mixture. (You can add 1/2 teaspoon of freshly grated nutmeg to the milk and egg mixture if you wish.)

    Egg and milk mixture added to the potato mixture in a baking dish

    The Spruce / Wanda Abraham

  8. Cover the baking dish with aluminum foil and place in a hot, preheated oven for 40 minutes. Remove from the oven and sprinkle the grated cheese over the top. Return to the oven uncovered for another five to 10 minutes (until the cheese is golden brown).

    Uncooked Potatoes Au Gratin in a baking dish

    The Spruce / Wanda Abraham

  9. When the cheese has melted, remove from oven and garnish with the fresh thyme if desired. Cut into squares and serve.

    Spanish Potatoes Au Gratin (Patatas Gratinadas) in a baking dish

    The Spruce / Wanda Abraham

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