Classic Spanish Tortilla with Potatoes and Onions

Quick Recipe Version (TL;DR)

• Yield: 6 servings (one 10-inch tortilla)
• Prep Time: 15 minutes
• Cook Time: 35 minutes
• Total Time: 50 minutes

Quick Ingredients

• 1 1/2 lb (680 g) Yukon Gold potatoes, peeled and thinly sliced (1/8-inch / 3 mm)
• 1 large yellow onion (10 oz / 285 g), thinly sliced
• 1 cup (240 ml) extra-virgin olive oil (you’ll reuse most of it)
• 8 large eggs
• 1 1/2 tsp (9 g) kosher salt, divided
• 1/2 tsp (1 g) freshly ground black pepper

Do This

• 1) Warm olive oil in a 10-inch skillet to 250°F (121°C).
• 2) Add potatoes, onion, and 1 tsp salt; cook gently at 240–260°F (116–127°C) for 18–22 minutes, stirring, until tender (not browned).
• 3) Drain potatoes/onions (save oil). Cool 5 minutes.
• 4) Beat eggs with remaining 1/2 tsp salt and pepper; fold in potatoes/onions; rest 5 minutes.
• 5) Heat 2 tbsp reserved oil in skillet over low heat (275°F/135°C pan surface) and cook tortilla 8–10 minutes until edges set.
• 6) Flip onto a plate, slide back in, and cook 4–6 minutes more; rest 10 minutes, slice, serve.

---

Why You’ll Love This Recipe

• Deeply comforting: Tender potatoes and sweet onions held together by custardy eggs.
• Simple ingredients, big payoff: Just eggs, potatoes, onions, olive oil, salt, and pepper.
• Make-ahead friendly: It slices beautifully and tastes great warm or at room temperature.
• Hearty and versatile: Works for breakfast, lunch, dinner, or tapas-style snacking.

Grocery List

• Produce: Yukon Gold potatoes, yellow onion
• Dairy: large eggs
• Pantry: extra-virgin olive oil, kosher salt, black pepper

Full Ingredients

Potatoes and Onions

• Potatoes: 1 1/2 lb (680 g) Yukon Gold potatoes, peeled, sliced 1/8-inch (3 mm) thick
• Onion: 1 large yellow onion (about 10 oz / 285 g), halved and thinly sliced
• Olive oil: 1 cup (240 ml) extra-virgin olive oil (most will be drained and saved)
• Kosher salt: 1 tsp (6 g), for cooking the potatoes and onion

Egg Mixture

• Eggs: 8 large eggs
• Kosher salt: 1/2 tsp (3 g)
• Black pepper: 1/2 tsp (1 g), freshly ground

For the Pan

• Reserved olive oil: 2 tbsp (30 ml) for cooking the tortilla (plus more if needed)

To Serve (Optional)

• Flaky salt (a pinch)
• Aioli or garlic mayonnaise
• Simple green salad

Step-by-Step Instructions

Step 1: Slice the potatoes and onions evenly

Peel the potatoes, then slice them into 1/8-inch (3 mm) rounds (or half-moons if the potatoes are large). Thin, even slices help everything cook at the same speed.

Halve the onion from root to tip and slice it into thin half-moons.

Step 2: Gently cook the potatoes and onion in olive oil (slow and tender, not crispy)

Set a 10-inch (25 cm) skillet over medium heat. Add 1 cup (240 ml) olive oil and heat until the oil reaches 250°F (121°C) (a thermometer is very helpful here).

Add the sliced potatoes, sliced onion, and 1 tsp (6 g) kosher salt. Reduce the heat to maintain the oil between 240–260°F (116–127°C). Cook for 18–22 minutes, stirring gently every few minutes, until the potatoes are fully tender and the onion is silky. You’re looking for a slow poach/confit texture, not browning.

If you notice any sizzling that seems aggressive or edges starting to brown, lower the heat to keep the oil in the target range.

Step 3: Drain and cool slightly (and save that flavorful oil)

Place a fine-mesh strainer over a heatproof bowl. Carefully pour the potato-onion mixture into the strainer to drain. Let it drain for 2 minutes, then spread the potatoes and onions on a plate or tray to cool for 5 minutes.

Do not discard the oil. It’s now potato-onion infused and can be reused for cooking the tortilla (and later for roasting vegetables, sautéing greens, or frying eggs).

Step 4: Mix eggs, seasoning, and the potato-onion mixture

In a large bowl, beat 8 large eggs until the whites and yolks are fully combined (about 30–45 seconds of whisking).

Whisk in the remaining 1/2 tsp (3 g) kosher salt and 1/2 tsp (1 g) black pepper.

Fold the drained potatoes and onions into the eggs. Let the mixture rest for 5 minutes. This short rest helps the potatoes absorb egg and makes the tortilla slice cleanly.

Step 5: Start cooking the tortilla low and slow

Wipe out the skillet and set it over low heat. Add 2 tbsp (30 ml) of the reserved olive oil and swirl to coat.

Heat the pan until the surface temperature is about 275°F (135°C) (use an infrared thermometer if you have one). The oil should shimmer gently, not smoke.

Pour in the egg-potato-onion mixture and spread it evenly. Cook on low heat for 8–10 minutes, occasionally running a silicone spatula around the edges to keep it from sticking and to help the sides form a neat round. The tortilla is ready to flip when the edges are set and the center is still slightly loose but no longer raw and runny.

Step 6: Flip confidently and cook the second side

Remove the skillet from the heat. Place a large plate (wider than the skillet) upside down over the skillet. Using oven mitts, hold the plate firmly against the pan and flip in one quick, confident motion so the tortilla lands on the plate.

Add 1 tbsp (15 ml) more reserved oil to the skillet if it looks dry, then slide the tortilla back into the pan, cooked side up.

Cook over low heat for 4–6 minutes, until the center is just set. For a more custardy interior, aim closer to 4 minutes; for a firmer slice, aim closer to 6 minutes.

Step 7: Rest, slice, and serve

Slide the tortilla onto a plate and let it rest for 10 minutes before slicing. Resting helps it finish setting and keeps slices neat.

Cut into 6 wedges. Serve warm or at room temperature, with a pinch of flaky salt if you like.

Pro Tips

• Control the oil temperature: Keeping the oil at 240–260°F (116–127°C) makes the potatoes tender and silky instead of crisp and browned (that’s the classic tortilla texture).
• Slice thickness matters: Aim for 1/8-inch (3 mm) potato slices so they soften evenly in the same time as the onions.
• Use the right pan size: A 10-inch (25 cm) skillet makes a thick, hearty tortilla with this ingredient amount.
• Flip with a flat plate: A rimless or low-rim plate gives the cleanest flip and easier slide back into the pan.
• Don’t rush the rest: The 10-minute rest time improves texture and makes slicing much cleaner.

Variations

• Chorizo tortilla: Stir in 4 oz (115 g) cooked, crumbled Spanish chorizo (or cured chorizo finely diced) with the potatoes before adding to the eggs.
• Roasted red pepper: Fold in 1/2 cup (85 g) drained, chopped roasted red peppers for a sweeter, brighter tortilla.
• Herb finish: Add 2 tbsp chopped parsley or chives to the egg mixture for a fresh lift.

Storage & Make-Ahead

Cool leftovers to room temperature within 2 hours, then refrigerate tightly covered for up to 4 days. Serve cold, bring to room temperature for 30 minutes, or rewarm gently in a skillet over low heat for 5–8 minutes. For clean slices, chill first, then slice and rewarm. You can also make the full tortilla a day ahead; it often tastes even better the next day as the flavors settle.

Nutrition (per serving)

Approximate, based on 6 servings (oil largely drained and not fully consumed): 290 calories, 11 g protein, 18 g carbohydrates, 21 g fat, 2 g fiber, 420 mg sodium.