Onion and Potato Spanish Tortilla

Ingredients

• 6eggs
• 400 gwhite potato, peeled and sliced about 2 mm thick
• 200 gonion, roughly one medium onion, sliced
• As needed (about 500–700 ml)extra virgin olive oil
• To tastesalt and pepper

Instructions

1. 1

   Soften the onion

   Warm a little olive oil in a pan over a medium heat. Add the onion and a pinch of salt, and cook until soft and translucent, then set it aside.

2. 2

   Cook the potatoes

   Put the potatoes in the same pan and add enough olive oil to cover them completely. Cook over a low heat for about 20–30 minutes; only a few bubbles should rise. They are ready when a toothpick passes through easily.

3. 3

   Cool the vegetables

   Lift the potatoes out with a slotted spoon and leave them to cool to room temperature. You can refrigerate the potatoes and onion at this stage and make the tortilla that evening or the next day.

4. 4

   Strain the oil

   Pour the olive oil through a sieve and set it aside. Use some to cook the tortilla, and save the rest for pan-frying onions, chicken or other food later.

5. 5

   Mix the filling

   Beat the eggs with a teaspoon of salt. Carefully fold in the onion and potatoes, taking care not to break the potato slices up too much.

6. 6

   Cook and flip

   Heat a 20 cm non-stick pan over a medium heat with a little of the reserved oil. Pour in half the tortilla mixture and cook for 2 minutes, or until golden underneath. Turn it out onto a plate, then slide it back into the pan with the uncooked side facing down.

7. 7

   Shape the tortilla

   As you slide it back into the pan, use a spatula to help neaten its shape.

8. 8

   Finish cooking

   After 2 minutes, or when golden underneath, take the tortilla out of the pan and place it on a serving plate.

What is Spanish tortilla?

Spanish tortilla, or tortilla española, is a thick egg dish made with potato and often onion. It is a familiar part of Spanish cooking, served in slices as a tapa, snack or simple meal.

This version cooks the vegetables gently in olive oil before mixing them with egg. That gives the potato time to soften without browning heavily, while the pan-fried finish forms a golden outside.

Nutrition and macros by portion

The nutrition label shows one serving as written: 170 calories, 7g protein, 16g carbs, 10g fat.

The potato supplies most of the carbohydrate, while the eggs provide protein and much of the tortilla's fat; the olive oil used for cooking can add a variable amount of fat depending on how much the ingredients retain. Pair a slice with salad or other vegetables for a more balanced plate.

The potato and onion

Thin slices: Cutting the potato to about 2 mm helps it cook evenly and makes it easier to fold into the egg mixture. Keep the slices intact when stirring so the finished tortilla has distinct pieces.

Soft onion: Cooking the onion separately until translucent gives it time to become tender before it is mixed with the egg. A pinch of salt helps season it as it cooks.

Gentle oil cooking

Low heat: The potatoes should cook slowly, with only a few bubbles rising through the oil. A vigorous sizzle can brown the outside before the centres are tender.

Doneness cue: Test a slice with a toothpick after about 20 minutes, then continue cooking if it still feels firm. The oil is strained after cooking, so it can be kept for another cooking use.

Mix without mashing

Cool first: Let the potatoes reach room temperature before combining them with the beaten eggs. The recipe also allows the cooked vegetables to be chilled and used later.

Gentle folding: Stir carefully so the potatoes remain in slices rather than breaking down into a mash. This helps the tortilla keep its layered, substantial texture.

Flipping in a small pan

Non-stick surface: The method specifies a 20 cm non-stick pan, which helps the egg mixture release for turning. Add only a little of the reserved oil to the pan.

Plate assist: After about 2 minutes, check that the underside is golden before turning the tortilla out onto a plate. Slide it back into the pan with the uncooked side down, using a spatula to tidy the edges.

Serving and timing

Rested or warm: The recipe finishes the tortilla on a serving plate once the second side is golden. It can be served warm or left to settle before cutting into slices.

On the side: Serve it with a green salad or sliced tomatoes for a fresh contrast. It also works as part of a spread with bread and other small dishes.

Recipe notes & tips

• Slice the potatoes evenly so they soften at a similar pace.
• Keep the heat low while the potatoes cook in the oil.
• Test the thickest potato slice with a toothpick before draining.
• Let the potatoes cool before mixing them with the eggs.
• Use a plate wider than the pan to make turning easier.
• Strain the leftover oil carefully and store it for another cooking use.

Variations

• Add herbs: Fold chopped parsley into the egg mixture for a fresh note.
• Add peppers: Soften sliced pepper with the onion before combining the vegetables with the egg.
• Add garlic: Cook a little finely chopped garlic with the onion for extra savoury flavour.
• Serve with salad: Pair a slice with dressed leaves or sliced tomatoes.
• Make smaller tortillas: Divide the mixture among smaller non-stick pans and adjust the cooking time to suit.

Common mistakes to avoid

• Heat too high: The potato can brown before it is tender; keep the oil at a gentle, barely bubbling heat.
• Uneven slices: Thick pieces may stay firm while thin ones soften; aim for slices about 2 mm thick.
• Breaking the potato: Vigorous mixing can turn the filling mushy; fold the onion and potato through the egg gently.
• Pan sticking: The tortilla may tear when turned; use the specified non-stick pan and coat it with a little reserved oil.
• Flipping too soon: The first side may not hold together; wait until it is golden underneath before turning it onto a plate.

How to store

Cool the cooked tortilla promptly, cover it and refrigerate for up to 3 days. Reheat gently in a pan over a low heat or serve chilled; avoid leaving it at room temperature for extended periods.

Frequently asked questions