The first weeks of my stay in Barcelona were an onslaught of sunlight and wine and salt. It was one of those blistering afternoons when I found myself in Ciutadella Park with Nieves and Judith, two Spanish girls I met in a hostel in Ireland two weeks before. They had invited me on a picnic. We found a shady spot at the edge of the park and sat down.

The picnic ended up being a four-hour Spanish feast. Along with pan con tomate, jamón iberico, picos (small, crunchy breadsticks), and a liter of a Catalonian chocolate milk drink called Cacaolat, Nieves and Judith had brought a Tupperware full of cubed tortilla de patatas. I provided humble essentials: salt, pepper, olive oil, broken Spanish. They were warm and talkative. We shifted the blanket to follow the shade.

Tortilla de patatas is not a Mexican-style tortilla but a thick disc made of potato, egg, and sometimes onion. Nieves told me it is usually eaten in triangular slices, like a pizza, but that cubing it was fine for potlucks and picnics. She had brought toothpicks to eat it with.

Historically tolerant of, but not enthused about, quiches and flans and other egg-forward foods that can be eaten cold, I went in with doubt. Any apprehension was demolished upon the first bite. The tortilla was nicely browned on the outside and not too eggy inside, the sliced potatoes still firm enough to provide a bit of bite. The onion, which Nieves said could be a divisive addition, added a sweet brightness.

After the picnic, I started seeing tortilla de patatas everywhere—prepackaged in grocery stores, listed on restaurant menus, and, once, on a paper plate held by a girl in the dorm elevator. And after Nieves shared her recipe with me, I’d see it come together in my dorm room kitchenette.

I ran into hurdles. The pans that came with the dorm did not come with lids. I let the onions cook too long and burn slightly. The biggest trial came when it was time to flip the tortilla onto a plate and slide it back into the pan to cook the other side. There was no plate large enough. So I washed and dried a cutting board while the egg set in the pan, then in one decisive motion overturned the pan onto the board and slid the tortilla back in successfully. I was so delighted that, had the tortilla exploded into flames, I still would have judged it a victory.

It did not explode. When the second side was cooked, I slid it onto a plate and cut it into triangles. Two friends came over, and we feasted. Positive reviews all around. And despite halving the recipe, there was enough for my roommate to microwave a slice for breakfast the next morning.

Nieves’s tortilla de patatas

Ingredients (for 4 people)
4 large potatoes
4 eggs
2 egg yolks (optional)
1 1/2 to 2 onions
salt to taste
olive oil

1. Cut the onions in julienne and the potatoes in cubes or slices.
2. Pour about an inch of olive oil into a pan, enough to later cover the potatoes almost completely. Turn the heat to medium.
3. Once the oil is hot, add the onions. Cook until soft.
4. Add the potatoes and a pinch of salt. Cook with the lid on until they are as soft as you want them. Stir occasionally.
5. Pour off most of the oil until only a couple of spoonfuls are left in the pan. (Here you can roast the potatoes and onions a little bit if you want.) Turn off the heat.
6. In a big bowl, crack the eggs. Add salt and egg yolks, if using. Stir until well mixed.
7. Fold the cooked potatoes and onions carefully into the bowl.
8. Turn the heat to high. Add a little more oil to the pan if needed.
9. Once the pan is hot, add the mixture back into it. Cook until the underside of the tortilla is well browned.
10. Put a plate over the pan and flip the pan over to transfer the tortilla onto the plate. Slide the tortilla back into the pan to cook the other side.
11. When the other side is cooked, it’s done!

Note: If you want the egg to be less done on the inside, turn the heat higher, leave the lid off, and cook for less time on each side.