Leeks can often contain hidden dirt so to ensure clean leeks, place the sliced pieces into a colander and rinse well. Once clean, shake out all the excess water or allow to thoroughly drain in the colander for a few minutes.
Heat olive oil in a large skillet on the stove top over medium high heat. When the oil is hot add leeks and garlic and saute until softened. Stir frequently to keep the leeks from burning and if necessary reduce to medium heat.