Slice the head of lettuce in half and separate the two halves. With the cut side facing your knife, cut at a diagonal angle to remove the core.
Then cut the half-head in half again and thinly slice away until each half is finely shredded. Do the same for the onions.
Next, place the lettuce in a bowl and add the vinegar and spices. Now’s the time to add a few shakes of hot sauce if you’d like!
Allow this to marinate at least 30 minutes before serving. This pickled lettuce is a great addition to tacos, sandwiches, and more!