Spanish Tortilla with Mushroom-Infused Oil
This Spanish tortilla starts with three ingredients, potatoes, onion, and eggs, cooked low and slow in olive oil and finished under the broiler. Serve it for brunch, lunch, or a light dinner, warm or at room temperature.
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The first time I remember having a Spanish tortilla was at a winery in California, and I was immediately struck by how something so simple could be so satisfying. Three ingredients, potato, onion, and eggs, cooked slowly in olive oil until the edges crisp and the center stays just barely set. I went home and started developing my own version that same week.
Since then, if I see a Spanish tortilla on a tapas menu, you can bet I’m ordering it. I’ve had several variations here in the U.S. and during travels to Spain. It’s one of those dishes that tells you a lot about a kitchen, the ratio of potato to egg, how much the onion has caramelized, whether the center is custardy or fully set. I’ve been developing recipes professionally since 2018 and this is one I keep coming back to, as it’s designed for home cooks.
My version uses mushroom-infused olive oil in place of plain olive oil, which adds an earthy, umami depth to every layer of potato. It’s an easy upgrade that makes this already impressive dish even more interesting. If you don’t have mushroom-infused oil on hand, plain olive oil works beautifully, or you can read below how to quickly make your own.
This Spanish tortilla works for brunch, lunch, or a light dinner. I like it right out of the pan or at room temperature. A slice of leftovers, cold from the fridge, might even taste better. It’s comparable to leftover pizza for me.
What You Need for Spanish Tortilla
The ingredient list is short. The technique is where the attention goes.
- Yukon gold potatoes: About 3 medium potatoes, thinly sliced to about ¼ inch. Yukon golds have thin skin and a buttery flavor that works perfectly for this Spanish tortilla. A mandolin makes the slicing faster and more uniform, though a sharp knife and patience works just as well.
- Yellow onion: Half a yellow onion, thinly sliced. It cooks down in the oil and adds a gentle sweetness between the potato layers.
- Eggs: Six eggs, whisked with 2 tablespoons of water, ½ teaspoon kosher salt, and ¼ teaspoon black pepper. The egg mixture is what binds the tortilla together and gives it that custardy center.
- Olive oil: A third of a cup. See the section below for your three options, plain, mushroom-infused, or store-bought infused oil.
- Kosher salt: Used to season each layer of potato as you build the tortilla in the skillet.
Choosing Your Olive Oil
Olive oil is the one ingredient in this recipe with the most flexibility, and it’s worth thinking through before you start.
- Plain olive oil is a traditional choice and the one most common for the dish. It lets the potato and egg flavor come through cleanly. Use a good quality extra virgin olive oil for the best result.
- Mushroom-infused olive oil is what this recipe was developed with, and it adds an earthy, umami layer that makes this version distinctly different from a classic tortilla. If you have a bottle of mushroom-infused oil (or other lightly flavored oil) on hand, it can add so much to the dish.
- DIY mushroom-infused olive oil is easy to make at home without any special equipment. Combine 3 dried shiitake mushrooms, roughly chopped, with 1 ½ cups of light olive oil in a small saucepan. Heat over the lowest possible flame for about 45 minutes to 1 hour, keeping the temperature well below a simmer. Strain out the mushrooms and let the oil cool before using. The flavor won’t be quite as concentrated as a longer infusion, but it will give the dish depth and umami goodness.
Store-bought mushroom-infused olive oil and other flavored oils are increasingly available at specialty grocery stores and online. This is the most convenient option if you want the flavor without making your own.
How to Make Spanish Tortilla
Prep and fry the potatoes. Wash and dry the potatoes. Slice thinly to about ¼ inch, using a mandolin if you have one. Thinly slice the onion and set aside. Heat the olive oil in an 8-inch to 10-inch oven-safe skillet over medium heat. Once hot, fry the potato slices in single-layer batches until browned but still soft, turning as needed. Drain on a paper towel-lined plate and repeat until all the potatoes are par-cooked.
Cook the onion. Remove all but about 1 tablespoon of oil from the skillet. Add the sliced onion and cook over medium heat for 3 to 5 minutes until translucent.
Layer the tortilla. Spread the onion evenly across the bottom of the skillet. Layer the potato slices on top in a circular pattern from the outside in, overlapping slightly, until the onion is covered. Sprinkle with remaining salt and pepper, seasoning as you go. Repeat with a second layer of potatoes, seasoning each layer. You should end up with at least 3 layers total.
Add the egg mixture. Whisk together the eggs, water, and salt in a large bowl until well combined. Slowly and evenly pour the egg mixture into the skillet over medium heat. Shake the skillet gently to help the egg distribute evenly. Once the edges begin to set, use a spatula to gently lift around the perimeter so any liquid egg can run underneath.
Broil and finish. Place the skillet under the broiler for 3 to 5 minutes, until the top begins to brown and the eggs are completely set. Remove carefully, as the handle will be very hot. Let rest on the stovetop for about 5 minutes.
Flip and serve. Place a large plate over the top of the skillet and carefully invert to release the tortilla. Slice into wedges and serve warm or at room temperature. Garnish with crispy mushrooms if desired.
Tips, Substitutions and Serving Ideas
- Serve it any temperature. Spanish tortilla is one of the few dishes that works warm, at room temperature, or cold from the refrigerator. In Spain it’s commonly served at room temperature as part of a tapas spread.
- Make it ahead. This stores well for up to 3 days in the refrigerator, covered. The flavors deepen overnight, making leftovers genuinely worth looking forward to.
- Whole30 compatible. This recipe is Whole30 compatible when made with plain olive oil. All three base ingredients, potatoes, onion, and eggs, are compliant.
- The flip takes confidence. The most intimidating step is inverting the tortilla onto a plate. Use a plate that’s slightly larger than your skillet, press it firmly on top, and flip in one decisive motion. A little hesitation is what causes spills. If you’re not comfortable with the flip, the tortilla is equally good served directly from the skillet in wedges without inverting.
- Scale up carefully. This recipe is built for an 8-inch to 10-inch skillet. A 12-inch skillet will produce a thinner tortilla with a shorter cook time. The ingredient ratios work well doubled in a 12-inch pan if you’re serving a larger group.
Whether you first encounter Spanish tortilla at a tapas bar, a winery, or on your own stovetop, it’s one of those recipes that earns a permanent place in your repertoire. Leave a star rating and let me know in the comments how you served it.
Spanish Tortilla
Ingredients
- 3 Yukon gold potatoes, thinly sliced to ¼ inch
- ½ yellow onion, thinly sliced
- ⅓ cup olive oil, plain, mushroom-infused, or store-bought infused, see notes
- 6 eggs
- 2 tablespoons water
- 1 teaspoon kosher salt, divided
- ½ teaspoon black pepper, divided
Instructions
- Wash and dry the potatoes and slice thinly to about ¼ inch. Heat olive oil in an 8-inch to 10-inch oven-safe skillet over medium heat.
- Fry potato slices in single-layer batches until just starting to brown but still soft. Drain on a paper towel-lined plate. Remove all but 1 tablespoon of oil from the skillet and cook the sliced onion for 3 to 5 minutes until translucent.
- Spread the onion evenly across the bottom of the skillet. Layer potato slices on top in a circular pattern, overlapping slightly, until the onion is covered. Season as you go with ½ teaspoon kosher salt and ¼ teaspoon black pepper. Repeat with a second layer of potatoes, seasoning each layer. You should have 3 to 4 layers total.
- Whisk together the eggs, water, ½ teaspoon kosher salt, and ¼ teaspoon black pepper in a large bowl until well combined. Slowly pour the egg mixture evenly over the potatoes over medium heat. Shake the skillet gently to distribute. Once edges begin to set, use a spatula to lift around the perimeter so liquid egg can run underneath.
- Place the skillet under the broiler for 3 to 5 minutes, until the top is lightly browned and eggs are completely set.
- Remove carefully, as the handle will be very hot. Rest on the stovetop for 5 minutes. Place a large plate over the skillet and invert confidently to release the tortilla. Slice into wedges and serve warm or at room temperature.
Notes
- Olive oil options: Plain extra virgin olive oil is traditional. Mushroom-infused olive oil adds earthy umami depth. To make your own, combine 3 dried shiitake mushrooms, roughly chopped, with 1½ cups light olive oil in a small saucepan. Heat over the lowest possible flame for 45 minutes to 1 hour without simmering. Strain and cool before using. Store-bought mushroom-infused oil is available at specialty grocers and online.
- Tips for the flip: Use a plate slightly larger than your skillet and flip in one confident motion. If you prefer, skip the flip and serve directly from the skillet in wedges. Make ahead: Stores well for up to 3 days in the refrigerator. Serve cold, at room temperature, or briefly warmed.
- Use a mandolin: Strongly recommended for uniform slices but not required. A sharp knife works with careful, consistent cutting.
- Optional garnish: Crispy sautéed mushrooms make a great finishing garnish and reinforce the mushroom-infused oil flavor. Chopped chives can add a pop of color.
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