How long lettuce can be cooked depends on the thickness of the cut and the cooking method. Generally speaking, it takes about 5 to 10 minutes to cook lettuce into thick slices or chunks. If the lettuce is cut into thin slices or filaments, the cooking time will be relatively shortened, and it will be cooked in about 2 to 3 minutes.

When cooking lettuce, you can blanch it with boiling water first, which can shorten the cooking time and retain the taste and nutrition of lettuce.