Spanish Tortilla With Potatoes and Caramelized Onions

Imperial August 8, 2026August 8, 2026

Quick Recipe Version (TL;DR)

Yield: 8 servings
Prep Time: 20 minutes
Cook Time: 40 minutes
Total Time: 1 hour 10 minutes, including resting

Quick Ingredients

2 pounds Yukon Gold potatoes, peeled and sliced 1/8 inch thick
1 large yellow onion, halved and thinly sliced
1 1/2 cups extra-virgin olive oil, divided
8 large eggs
1 1/2 teaspoons fine sea salt, divided
1 tablespoon finely chopped fresh flat-leaf parsley

Do This

1. Heat the olive oil to 300°F in a deep 10-inch nonstick skillet.
2. Cook the onion for 8 minutes, then add the potatoes and 1/2 teaspoon salt. Cook at 300–325°F for 22 minutes.
3. Drain the potato mixture for 5 minutes, reserving the flavorful oil.
4. Beat the eggs with the remaining 1 teaspoon salt, fold in the warm potatoes and onions, and rest for 10 minutes.
5. Heat 1 tablespoon reserved oil in the skillet. Add the egg mixture and cook for 6 minutes, lowering the heat after the first minute.
6. Cover the skillet with a large plate, carefully invert the tortilla, and slide it back into the skillet.
7. Cook the second side for 3 minutes, then rest for 10 minutes before slicing.

Why You’ll Love This Recipe

Slow-cooked potatoes become exceptionally tender and creamy without falling apart.
Thinly sliced onion turns sweet and golden as it cooks in olive oil.
The center stays moist and custardy while the outside develops a beautiful golden crust.
It tastes equally delicious warm, at room temperature, or chilled for an easy make-ahead meal.

Grocery List

Produce: 2 pounds Yukon Gold potatoes, 1 large yellow onion, and 1 small bunch flat-leaf parsley
Dairy: 8 large eggs
Pantry: Extra-virgin olive oil and fine sea salt

Full Ingredients

For the Potatoes and Onions

2 pounds Yukon Gold potatoes, peeled and cut into even 1/8-inch slices
1 large yellow onion, about 10 ounces, halved and thinly sliced
1 1/2 cups extra-virgin olive oil, divided
1/2 teaspoon fine sea salt

For the Egg Mixture

8 large eggs, at room temperature
1 teaspoon fine sea salt

For Serving

1 tablespoon finely chopped fresh flat-leaf parsley

Spanish Tortilla With Potatoes and Caramelized Onions – Closeup

Step-by-Step Instructions

Step 1: Prepare the potatoes and onion

Peel the potatoes and cut them into uniform 1/8-inch slices. A mandoline makes this quick, but a sharp chef’s knife works well, too. Halve the onion from root to stem, remove the peel, and cut it into thin half-moons. Keeping the potato slices a consistent thickness helps them cook evenly and form distinct, tender layers in the finished tortilla.

Step 2: Slowly cook the onions and potatoes

Pour the olive oil into a deep 10-inch nonstick skillet with sides at least 2 1/2 inches high. Heat the oil over medium-low heat until it reaches 300°F on an instant-read thermometer. Add the sliced onion and cook for 8 minutes, stirring every 2 minutes, until softened and beginning to turn golden.

Carefully add the potatoes and sprinkle them with 1/2 teaspoon fine sea salt. Turn the slices gently with a silicone spatula so they are coated in oil. Maintain the oil between 300°F and 325°F and cook for 22 minutes, turning the mixture gently every 4 to 5 minutes. The potatoes are ready when a paring knife slides through the center of a slice without resistance. They should be tender but not crisp or deeply browned.

Step 3: Drain the potato mixture

Set a heatproof colander over a large bowl. Carefully pour in the potatoes, onions, and oil, then let the mixture drain for 5 minutes. Handle the potatoes gently so the slices remain mostly intact. Reserve the drained olive oil; you will need 1 tablespoon for finishing the tortilla, and the remainder can be cooled and refrigerated for another use.

Step 4: Combine the potatoes with the eggs

Crack the eggs into a large mixing bowl. Add the remaining 1 teaspoon fine sea salt and whisk for 30 seconds, just until the yolks and whites are completely combined. Do not whip in a large amount of air. Fold the warm potato and onion mixture into the eggs with a flexible spatula, making sure all the potato slices are coated. Let the mixture rest for 10 minutes. This allows the potatoes to absorb some of the egg and helps create the tortilla’s characteristic custardy texture.

Step 5: Cook the first side

Wipe out the skillet and return it to medium heat. Add 1 tablespoon of the reserved olive oil and heat for 1 minute, until the oil is shimmering and approximately 350°F. Pour in the egg and potato mixture, spreading it evenly with a spatula. Cook over medium heat for 1 minute, gently shaking the pan to prevent sticking.

Reduce the heat to low and cook for 5 additional minutes. Run a silicone spatula around the edge several times, gently pressing the sides inward to create a rounded shape. The edges and bottom should be set and lightly golden, while the surface remains glossy and partially unset.

Step 6: Flip the tortilla

Loosen the tortilla around the edges and underneath with a flexible spatula. Place a flat plate at least 12 inches wide over the skillet. Wearing oven mitts, hold the plate firmly against the skillet with one hand and grasp the skillet handle with the other. In one quick, confident motion, invert the skillet so the tortilla lands cooked-side up on the plate.

Return the empty skillet to low heat. If the surface looks dry, brush it with a small amount of oil left on the plate. Gently slide the tortilla from the plate back into the skillet so the uncooked side is facing down. Wash the plate before using it again for serving because it may have touched partially cooked egg.

Step 7: Finish cooking and rest

Cook the second side over low heat for exactly 3 minutes, using the spatula to tuck in and round the edges. The tortilla should feel softly set when pressed in the center and reach at least 160°F in the thickest part. For a firmer center, cook for 1 additional minute.

Slide the tortilla onto a clean serving platter and let it rest for 10 minutes. Sprinkle with the chopped parsley, then cut into 8 thick wedges. Serve warm or allow it to cool completely to room temperature.

Pro Tips

Choose the right potatoes: Yukon Gold potatoes hold their shape while developing a creamy texture. Avoid very floury potatoes, which can break down and make the tortilla dry.
Keep the oil gentle: The potatoes should slowly poach rather than fry. If they begin sizzling aggressively or browning at the edges, lower the heat.
Use a reliable nonstick skillet: A well-seasoned carbon-steel skillet also works, but avoid stainless steel because the eggs are more likely to stick during the flip.
Do not skip the egg soak: Resting the warm potatoes in the beaten eggs for 10 minutes helps bind the layers and produces a custardy interior.
Flip with confidence: Use a plate wider than the skillet, clear the surrounding work area, and make the turn in one smooth motion.

Variations

Potato-only tortilla: Omit the onion and increase the potatoes to 2 1/4 pounds for a simple, traditional variation.
Roasted pepper tortilla: Fold 1/2 cup drained, thinly sliced roasted red peppers into the egg and potato mixture before its 10-minute rest.
Chorizo tortilla: Brown 4 ounces of diced Spanish chorizo for 3 minutes, drain it, and fold it into the mixture before cooking the tortilla.

Storage & Make-Ahead

Allow the tortilla to cool before storing, but do not leave it at room temperature for longer than 2 hours. Place leftovers in an airtight container and refrigerate for up to 4 days. Serve chilled, let individual slices stand at room temperature for 20 to 30 minutes, or warm them in a 300°F oven for 10 to 12 minutes. Individual slices can also be microwaved at 50 percent power in 30-second intervals. For the best texture, avoid freezing. The fully cooked tortilla may be made 1 day in advance, refrigerated, and brought toward room temperature before serving.

Nutrition (per serving)