Cut kale into 1-inch pieces. Toss the kale in a large bowl with the olive oil and spread evenly on two baking sheets, making sure the pieces are in one layer. (Do not salt. Salt will draw out moisture and cause the kale to not crisp.)
Bake them for about 8-10 minutes, or until crispy, making sure to flip them around half way though. Season with salt, pepper and crushed red pepper flakes.