Tortilla Espanola (its relation to Mexican tortillas comes solely from its round shape) is among the most popular dishes in Spain. Although its ingredients couldn't be more basic--potatoes, eggs, onions, and oil--they're combined and cooked in a way that makes this dish irresistible and versatile.

The potatoes are normally fried, but we've roasted them with excellent results. Unlike American omelets, this one's best made several hours ahead then served at room temperature.

Step 1:
Roast potatoes before adding them to the eggs for the omelet.

Step 2:
Combine potatoes and eggs, and let stand 10 minutes. This allows the potatoes to absorb the eggs. Pour mixture into a nonstick pan. When set, invert onto a plate, sliding the omelet back into the pan to cook the other side.