Equipment
* optional
Ingredients
Produce
- 500 g yukon gold potato, peeled
- 1 yellow onion, peeled and halved
Egg Base and Cooking Medium
- 6 egg, room temperature
- 200 ml extra virgin olive oil, liquid
- 5 g fine sea salt, fine crystal
Garnish
- 5 g flat-leaf parsley, finely chopped
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 274 kcal
- Protein
- 12 g
- Carbohydrates
- 24 g
- Fat
- 14 g
- Sugar
- 3 g
- Zinc
- 1.4 mg
- Water
- 159 g
Sources: Aggregated Public Data, USDA FoodData Central
Method
Peel the potatoes completely using a vegetable peeler over a cutting board.
Slice the peeled potatoes and yellow onion into uniform 3 mm (1/8-inch) rounds using a mandoline slicer or chef knife.
Whisk the room temperature eggs and fine sea salt together in a large mixing bowl for 60 seconds until completely uniform and lightly aerated.
Heat the extra virgin olive oil in a 25 cm oven-safe nonstick skillet over medium-low heat until it reaches 120°C (250°F).
Add the sliced potatoes and onions to the warm oil and poach gently over low heat for 18 minutes, turning occasionally with a silicone spatula, until tender throughout without browning.
Drain the cooked potato and onion mixture through a colander positioned over a heatproof bowl to collect the cooking oil.
Fold the warm drained potatoes and onions into the whisked eggs in the large mixing bowl using a silicone spatula.
Rest the egg and potato mixture at room temperature for 10 minutes to allow warm starches to absorb the seasoned liquid egg.
Preheat the oven broiler to high at 230°C (450°F) with the top oven rack set 15 cm (6 inches) below the heat source.
Pour 30 ml of the strained, warm olive oil back into the 25 cm oven-safe nonstick skillet over medium heat, then pour in the rested egg and potato mixture.
Simmer the omelet undisturbed over medium-low heat for 4 minutes until the bottom crust sets and the edges pull slightly away from the pan walls.
Broil the open-faced omelet on the upper rack of the oven for 3 minutes until the surface is puffed, lightly golden, and an instant-read food thermometer inserted into the center reads at least 71°C (160°F).
Rest the skillet on a wire cooling rack for 5 minutes so the residual heat finishes setting the delicate interior custard.
Garnish the top of the warm omelet with the finely chopped flat-leaf parsley across its entire surface.
Serve the open-faced omelet warm directly from the pan or slide onto a serving platter and slice into generous wedges with a chef knife.
Chef's Notes
- Confit poaching is the foundational secret: gently simmering sliced potatoes in warm extra virgin olive oil creates a meltingly creamy core without developing leathery fried crusts.
- The 10-minute soaking period between draining the hot potatoes and cooking the omelet allows surface starches to gelatinize and bind intimately with the beaten eggs, guaranteeing clean slices that do not crumble.
- Do not discard the strained poaching olive oil; pour it through a fine strainer into a glass jar and refrigerate to use as an exceptionally flavorful cooking oil for roasted vegetables, fried eggs, or vinaigrettes.
- To ensure food safety for pregnant or immunocompromised diners, confirm the center reaches 71°C (160°F) using an instant-read thermometer, or substitute pasteurized shell eggs.
Storage
Refrigerator: 3 days — Store wedges in an airtight container lined with parchment paper at or below 4°C (40°F).
Reheating: Reheat gently in an oven preheated to 150°C (300°F) for 8 to 10 minutes until warm throughout, or reheat in a covered dry skillet over low heat for 3 to 5 minutes. The dish is also traditionally enjoyed at room temperature.
Troubleshooting
The bottom surface of the omelet burns before the center is ready for broiling
Cause: The stovetop burner was set too high during the initial bottom-setting phase, scorching the delicate egg base.
Fix: Transfer the skillet immediately beneath the broiler to finish cooking entirely from above, then slice and discard the bottom crust before serving.
Prevention: Regulate stovetop heat to medium-low and use an oven-safe skillet with a heavy, heat-diffusing base.
The omelet weeps watery liquid and breaks apart upon slicing
Cause: Potatoes and onions were not drained thoroughly, or the egg custard was undercooked below safe curdling temperature.
Fix: Return the skillet under the broiler on the middle oven rack for 90 seconds to drive off excess moisture and firm the core.
Prevention: Drain vegetables in a colander for at least 2 minutes and verify the center registers 71°C (160°F) before removing from heat.
Cultural Context
Rooted in the Spanish tradition of tortilla de patatas, this open-faced interpretation mirrors the rustic tavern style of presenting flat, broiled egg tortillas topped with herbs. Originating in 19th-century Navarre as an ingenious, economical staple for rural workers, the humble marriage of local potatoes, farm eggs, and olive oil has transcended class lines to become the undisputed symbol of Spanish culinary heritage.
