1. Bring a large saucepan of lightly salted water to a boil over high heat. Add the peas and boil for 5 minutes, or until just tender. Use a wire sieve to transfer the peas to a bowl of cold water. Return the pan to a boil, add the broccoli, and boil for 4 minutes, or until just tender. Transfer the broccoli to the peas and cool. Drain the vegetables together and pat dry with paper towels.

2. Heat 4 tbsp of the oil in a 9in (23cm) nonstick frying pan over medium heat. Add the potatoes and onion. Cook, stirring occasionally, for 10–15 minutes, or until the potatoes are tender. Let cool slightly.

3. Beat the eggs in a large bowl, and season with salt and pepper.

4. Use a slotted spoon to transfer the potatoes and onions to the eggs. Add the peas and broccoli and gently stir. Wipe out the pan with paper towels.

5. Heat the remaining 2 tbsp oil in the pan over high heat. Pour in the egg mixture, reduce the heat to low, and smooth the surface. Cook gently for 20–25 minutes or until the top begins to set and the underside is golden brown.

6. Carefully, slide the tortilla on to a plate. Place a second plate on top and invert both together so that the cooked side is on top. Slide the tortilla back into the pan and cook for 5 minutes, until the underside is golden brown.

7. Let stand for at least 5 minutes. Invert onto a serving platter. Serve warm or cooled, cut in wedges.

Variation:

Quick Tortilla: For simple tortilla, omit the peas and broccoli. Substitute red-skinned potatoes, cut into matchsticks, and cook for about 10 minutes.