The most common method of preparing Brussels sprouts for cooking begins with cutting the buds off the stalk. Any surplus stem is cut away, and any loose surface leaves are peeled and discarded. Once cut and cleaned, the buds are typically cooked by boiling, steaming, stir frying, grilling, slow cooking, or roasting. This process is done for up to 45 minutes and to ensure even cooking throughout, buds of a similar size are usually chosen. Some cooks make a single cut or a cross in the center of the stem to aid the penetration of heat. The cross cut may, however, be ineffective, with it being commonly believed to cause the sprouts to be waterlogged when boiled.