never knew this.. but going to try it.

I made my first batch of Mojo de Ajo last year, here is the recipe I followed:
www.rickbayless.com/recipe/view?recipeID=244

Fantastic stuff with a multitude of uses. Latest use for me was to use a few tablespoons in a sturdy pot, heated until sizzling, put in 1.5 lbs of Manila clams & a good splash of white wine. Shake pan a few times while clams are opening.

Serve in a bowl w/clams, some broth & a hunk of French bread, delicious.

Can you user pre-peeled garlic for this (often cheaper for some reason)?

I've now used both and pre-peeled garlic (cloves) was fine. You are correct, pre-peeled garlic (cloves) can be very cheap sometimes, (in Chicago at the Korean grocery markets).