Tortilla Española (Spanish Omelette)

Preheat oven to 350ºF.

Peel and thinly slice the onion and the potatoes (if using red or another soft-skinned potato, you may choose to leave the skin on). Place in a large microwave-safe bowl and toss with a nice drizzle of olive oil, a big pinch of salt and a few grinds of fresh black pepper. Microwave on high for 7-10 minutes, stirring once, or until the potatoes are just cooked through. Once cooked, remove from microwave and allow to cool slightly.

Once the potatoes and onions have cooled slightly (you can speed up this process by sticking them in the freezer for a few minutes), in a separate bowl whisk the eggs with another pinch of salt and a few more grinds of pepper. Add the eggs to the potatoes and onions, stirring to coat.

Heat a tablespoon of olive oil in a 10-inch, oven-safe non-stick skillet over medium-high heat. Add the potato and egg mixture to the hot pan, spreading out the potatoes to evenly cover the pan. Allow to cook for 3-5 minutes, or until the edges of the tortilla are set.

Transfer the pan to the preheated oven and bake for 10-15 minutes, or until the center of the eggs are set. Remove from the oven and invert onto a plate, so that the bottom of the tortilla is now on top.

Serve warm or, more traditionally, at room temperature or cold. Will keep, well-wrapped in the fridge, for 3 days.