Tortilla with Tuna & Onions

Heat 1 1/2 teaspoons oil in a medium nonstick skillet over medium-low heat. Add onions and 1/4 teaspoon salt. Cook, stirring often, until very tender and starting to turn light golden, 10 to 20 minutes. (Add 1 to 2 tablespoons water, if onions are browning too quickly.) Add tomatoes and cook, stirring occasionally, until tomatoes have melted into the onions, about 10 minutes. Season with pepper; set aside to cool.

Whisk together eggs, egg whites and remaining 1/4 teaspoon salt in a bowl. Fold in tuna and reserved onion mixture with a rubber spatula.

Wash pan, wipe dry and brush with remaining 1 teaspoon oil. Place over low heat. Add the egg mixture and stir gently to distribute tuna and onions. Cook over low heat until underside is golden and top is starting to set, about 5 minutes.

Use a spatula to loosen tortilla, then slide it onto a plate. Invert it back into the pan and cook until the bottom is set, about 1 minute. Slide onto a serving platter and cut into wedges. Serve hot or at room temperature.

Alternative Cooking Method

If flipping a large tortilla makes you nervous, finish the tortilla by placing the skillet under the broiler until the top is set and golden brown, about 2 minutes. Slide the finished tortilla onto a platter and serve.