Heat oil in a large, heavy saucepan for about 7 minutes. Ensure oil is hot enough by sticking the end of a wooden spoon into the oil; bubbles should form around the wood start to float up.
Place 1 tortilla on a slotted spoon and bottom of 1 jar on top of tortilla; lower into the hot oil. Carefully remove spoon, making sure not to tear the tortilla. Mold tortilla around the bottom of the jar using the spoon; cook for about 1 minute.
Remove the jar and tortilla bowl from oil using tongs, tilting the tortilla bowl so excess oil goes back into the saucepan. Lay bowl on a paper towel-lined plate to drain and cool. Repeat with remaining tortillas and jars.