Spanish Potato and Onion Omelet (Tortilla de Patatas)

Why You’ll Love This Recipe

• Classic Spanish comfort: silky eggs, sweet onions, and tender potatoes in one golden cake.
• Creamy, custardy middle with a bronzed crust you can slice into neat wedges.
• Great hot, warm, or at room temperature—breakfast, lunch, tapas, or picnic.
• Beginner-friendly flip technique, plus an oven finish option if you prefer.

Grocery List

• Produce: 700 g waxy potatoes, 1 large yellow onion, flat-leaf parsley (optional)
• Dairy: 6 large eggs
• Pantry: Extra-virgin olive oil, kosher salt, black pepper, flaky sea salt (optional)

Full Ingredients

For the tortilla

• 700 g waxy potatoes (e.g., Yukon Gold), peeled and thinly sliced 3 mm (1/8 inch)
• 1 large yellow onion (about 250 g), thinly sliced
• 6 large eggs (about 300 g), room temperature
• 1 cup (240 mL) extra-virgin olive oil, plus 2 tbsp reserved for the pan
• 1 1/4 tsp kosher salt, divided (1/2 tsp for potatoes/onion, 3/4 tsp for eggs)
• 1/4 tsp freshly ground black pepper

To serve (optional)

• 1 tbsp chopped flat-leaf parsley
• Flaky sea salt
• Aioli or a simple green salad, for the table

Step-by-Step Instructions

Step 1: Prep and slice the vegetables

Peel the potatoes and slice them into thin, even 3 mm (1/8 inch) rounds. Halve and thinly slice the onion. Even slices help the tortilla cook evenly and set neatly. Crack the eggs into a large bowl so they can lose their chill while you cook the vegetables.

Step 2: Gently fry the potatoes and onion

In a 10–12 inch skillet or saucepan, heat 1 cup (240 mL) olive oil over medium-low. If using a thermometer, aim for 240–260°F (115–125°C); the oil should shimmer with a gentle, steady sizzle. Add potatoes, onion, and 1/2 tsp salt. Cook, stirring occasionally and adjusting heat to avoid browning, until the potatoes are tender throughout and the onions are soft and sweet, 15–18 minutes.

Step 3: Drain and season

Set a sieve over a bowl. Carefully drain the potato-onion mixture, reserving the oil. You will need 2 tbsp of this flavorful oil for cooking the tortilla; save the rest for salads or future cooking. Let the vegetables cool until warm, 3–5 minutes, so they do not scramble the eggs in the next step.

Step 4: Beat eggs and combine; rest 10 minutes

Beat the eggs with the remaining 3/4 tsp salt and the black pepper. Gently fold in the warm potatoes and onions until coated. Let the mixture rest for 10 minutes—this hydrates the eggs with potato starch and yields a custardy center.

Step 5: Cook the first side

Heat an 8 inch (20 cm) nonstick or well-seasoned carbon steel skillet over medium heat. Add 2 tbsp of the reserved oil. When the oil is hot, scrape in the egg-potato mixture, smoothing the top and pressing the sides slightly to form a rounded edge. Cook 5–6 minutes, shaking the pan occasionally and running a spatula around the edge, until the sides are set and the center is still jiggly.

Step 6: Flip and finish the tortilla

Place a flat plate larger than the pan over the skillet. Using oven mitts, invert the pan so the tortilla lands on the plate. Slide it back into the skillet, uncooked side down. Cook 3–4 minutes more. For a very custardy center, cook an additional 1–2 minutes; for a firmer set, cook 2–3 minutes more. Optional oven finish: after Step 5, transfer the skillet to a 375°F (190°C) oven for 6–8 minutes to set the top without flipping; broil 30–60 seconds at the end for extra color if desired.

Step 7: Rest, slice, and serve

Transfer the tortilla to a board or plate and rest 5–10 minutes for the juices to settle. Sprinkle with parsley and flaky sea salt. Slice into 6–8 wedges. Serve warm, at room temperature, or chilled—delicious any time of day.

Pro Tips

• Use waxy potatoes for tender slices that hold their shape; starchy varieties can crumble.
• Resting the egg-potato mixture for 10 minutes is key to a custardy, cohesive interior.
• Keep the oil gently hot when frying the potatoes and onion—soft and silky, not browned or crisped.
• Choose an 8 inch (20 cm) skillet for a thick, juicy tortilla; a 9 inch (23 cm) skillet yields a slightly thinner one.
• If a crack forms during flipping, press the sides gently with a spatula to seal while the eggs are still soft.

Variations

• With pimentón and peppers: Fold in 1/2 tsp smoked paprika and 1/2 cup chopped roasted red peppers with the eggs.
• Herb-forward: Add 2 tbsp finely chopped parsley and chives to the egg mixture for a fresh finish.
• Chorizo twist: Sauté 75 g diced Spanish chorizo in 1 tsp oil until it renders, then fold into the egg mixture.

Storage & Make-Ahead

Cool to room temperature (about 30 minutes), then cover and refrigerate up to 3 days. Serve cold or gently rewarm slices in a nonstick skillet over low heat 3–4 minutes per side or in a 300°F (150°C) oven for 10–12 minutes. The potato-onion mixture can be fried up to 2 days ahead; store covered in some of the reserved oil and combine with eggs just before cooking. Freezing not recommended for best texture.

Nutrition (per serving)

Approximate for 1 of 6 wedges: 290 calories; 19 g fat; 23 g carbohydrates; 8 g protein; 540 mg sodium. Values vary depending on how much oil is retained.