Brandon Boudet, chef at Dominick's, Little Dom's, the 101 Coffee Shop, and Tom Bergin's (all in Los Angeles), created this version of Spain's classic potato omelet. This is a good recipe for your entertaining short list because you can make it ahead, it's versatile enough to be an appetizer or vegetarian main, and it's good warm or at room temperature.
2 large russet potatoes (1 1/2 lbs. total), peeled and put in a bowl of water
Preheat oven to 300°. Cut half a potato into about 1/8-in.-thick slices. Heat 1 tbsp. oil in a seasoned 10-in. cast-iron skillet or ovenproof nonstick frying pan over medium-low heat. Add a layer of potatoes and sprinkle with some salt and pepper. Cook, turning once, until potato slices are just tender and only barely browned, 5 to 8 minutes. Transfer from pan to a plate. Repeat cutting and cooking with half a potato at a time, salt, and pepper, adding additional oil as needed.
Add 1 more tbsp. oil to pan and increase heat to medium. Layer all the potatoes in pan; pour eggs on top. Cook until underside is golden, 3 to 5 minutes.
Bake until eggs are set when pan is shaken, about 20 minutes. Let tortilla stand at least 10 minutes. Loosen from pan with a flexible spatula. Gently invert tortilla onto a platter or board. Sprinkle with parsley. Cut into wedges and serve warm or at room temperature with romesco.
Make ahead: Up to 3 hours; serve at room temperature.
Dominick's, Little Dom's, the 101 Coffee Shop, and Tom Bergin's, all in Los Angeles