Call it what you like, potato and onion omelette or Spanish tortilla: either way, it is an absolute classic and a very dependable thing to cook.

Quick info

  • Servings: 4
  • Prep: 1 hour 15 minutes
  • Cooking: variable (potato cooking time + omelette cooking time)
  • Tools: 22, max 24 cm (8.7–9.4 in) frying pan (if pan-cooking) or oven dish/tray (if oven-cooking); knife; chopping board; large and small bowls; flat plate for flipping the tortilla (only if pan-cooking)

Ingredients

  • 500g (17.6 oz) potatoes
  • 4 eggs
  • 1 medium onion (not too small)
  • oil to taste
  • salt to taste
  • pepper to taste
  • (optional) 2–3 sprigs of rosemary

Method

  1. Prep the potatoes. Slice 500g (17.6 oz) of potatoes very thinly (about 2 mm / 0.08 in, or they’ll never cook through) — ideally with a mandoline, so they’re uniform and cook evenly. Soak the slices in cold water, then drain and pat them really dry with a tea towel.

  2. Cook the potatoes in the pan. In a max 24 cm (9.4 in) pan, heat enough oil to cover them, along with 2–3 sprigs of rosemary. Once the oil is hot, fish out the rosemary and add the potatoes. Cook over medium heat, turning often and adjusting the flame as needed: they should poach gently, not fry. Season lightly during cooking. Keep going until the potatoes are very soft and start to break apart.

  3. Add the onion. Slice 1 medium onion thinly. Add it to the potatoes once they start breaking up. Keep cooking, still over medium heat, until the onion is completely soft and well combined with the potatoes.

  4. Beat the eggs. In a small bowl, beat 4 eggs with salt to taste and pepper to taste.

  5. Combine potatoes and eggs. Lift the potatoes and onion out of the pan and let them cool slightly. Once warm, add them to the eggs in the large bowl and stir gently.

  6. Cook the tortilla — pick your method.

    • Option A · In the pan: Put the max 24 cm (9.4 in) pan back on the heat and add 3–4 tablespoons of oil. Pour in the mixture and cook over medium-high heat, with a lid on. Once the bottom is well cooked and golden and the top is still soft, flip the tortilla using a flat plate. Slide it back into the pan and finish cooking the other side, adjusting the heat as needed.
    • Option B · In the oven: Pour the mixture into a lightly oiled oven dish/tray. Bake in a static oven at 180°C (356°F) for 25–30 minutes, until set and golden. For extra colour, give it the last 5 minutes under the grill.

  7. Serve. Serve the tortilla hot or cold.