Slice the potatoes into large matchsticks and lightly spray them with canola oil. Season with salt and pepper. Arrange potato slices on a wire rack and place rack on a half-sheet pan. Bake until golden brown, about 30 minutes. When fries are almost finished baking, make cheese sauce. Serve fries with cheese sauce for dipping.
Dice cheese into equal-size cubes. Pour chili into a small saucepan and add diced cheese. Stir slowly over medium heat until melted, about 5 minutes.