Put an oven rack in the centre of the oven. Preheat the oven to 350 degrees F.
In a medium bowl, whisk the egg whites until fluffy, about 30 seconds. Add the cream, lox, lemon zest, salt, and pepper.
In a 10-inch, ovenproof, nonstick skillet, heat the oil over medium heat. Add the arugula and garlic. Cook, stirring frequently, until the arugula has wilted, about 1 minute. Pour the egg mixture into the pan and stir to combine the ingredients. Cook, without stirring for 4 minutes. Transfer the skillet to the oven and bake until set, about 10 to 12 minutes.
Slide the frittata onto a platter. Using a serrated knife, cut the frittata into wedges and serve warm or at room temperature.
Recipe courtesy of Giada De Laurentiis