In a deep 4-quart pan, heat 1 1/2 inches canola oil to 375 degrees F. Float 1 tortilla on top of the oil. With the bowl of a metal ladle, press down on the center of the tortilla until it touches the bottom of the pan and oil bubbles up around the tortilla. Hold tortilla down until it is golden brown, about 2 minutes. Lift from oil with tongs and a slotted spoon and drain over pan. Let cool and drain on paper towels. Repeat to cook the remaining tortillas (if made the night before, store in airtight container).