Cut leek in half lengthwise, then cut each piece in half crosswise. Cut each quarter into long, thin strips. Rinse the strips in hot water and pat dry.
Toss in a medium bowl with oil.
In a small bowl combine flour, paprika, garlic powder, salt and pepper.
Sprinkle flour and spice mix over leeks; toss well to combine.
Spread in an even layer on a baking sheet. Bake, stirring once or twice, until the leeks are crispy and golden brown, 10 to 12 minutes.