Corned beef is a beef brisket that soaks in brine and then cures with salt and seasonings. This meat gets its distinctive pink color from sodium nitrate which is an ingredient in the curing process. It is a tough cut of meat, so it's always best to cook corned beef for a long period of time so that it becomes tender. Typical cooking methods include boiling, slow cooking or oven roasting the meat, as well as using an Instant Pot or other pressure cooker.