Preheat oven to 400°F. Put potato strips, two egg whites and a pinch of Tex-Mex spice in a container with a lid. Shake to coat strips. Lightly spray a cookie sheet with oil, and spread the strips in a single layer. Bake for 30 minutes, or until browned and crispy.
Meanwhile, in a medium bowl, mix turkey plus remaining egg whites and Tex-Mex spice. Make into six patties. Spray a saucepan with oil and place on medium heat. Cook burgers for about six minutes, until brown on the bottom. Flip, and cook for another six minutes, or until done.
Place each patty on a bun and top with avocado slices and salsa, if desired. Serve with a side of fries.
Per serving: 415 calories, 27 g protein, 14 g fat (3 g saturated fat), 45 g carbohydrates, 8 g fibre, 66 mg cholesterol, 269 mg sodium