Heat the oil in an 8-inch skillet over medium-high heat until it reaches 350 degrees—the oil should be shimmering and a small piece of tortilla should sizzle immediately when dropped in.

Using tongs, slip half of a tortilla into the oil and submerge it with a metal spatula for 30 seconds until just set but not yet browned.

Fold the remaining half of the tortilla over with the tongs to create a U-shape, holding it open slightly so there is about a 1-inch gap between the sides.

Fry until the shell is light golden brown and crisp, about 1 to 2 minutes, turning it as needed to ensure even cooking.

Transfer the finished shell to a paper towel-lined plate to drain. Serve immediately while still warm and crackling.