Preheat the oven to 400 degrees. Slice each potato into 1/4 inch
ovals, then slice each oval lengthwise into matchsticks. Coat a
baking sheet with 3 sprays of the vegetable oil. Combine the egg
whites and Cajun spice in a bowl. Add the matchstick potatoes and mix
to coat. Pour the coated potatoes onto the prepared baking sheet and
spread them out into a single layer, leaving a little space in
between. Place the baking sheet on the bottom shelf of the oven. Bake
for 40-45 minutes, until the fries are crispy, turning them every 6
to 8 minutes with a spatula so that they brown evenly.
Source: "In the Kitchen with Rosie".
