Cook times and methods will differ slightly depending on the food, but you can use this simple process to prepare most fruits, vegetables, meats, and grains for baby. From Cooking Light First Foods by Carolyn Land Williams, M.Ed., R.D.
Wash or peel the produce you'd like to use for your pureed baby food; cut the food into smaller pieces.
Steam, boil, or bake the food until it’s very tender.
Process or mash the cooked food until it’s smooth or until desired consistency is reached.
Spoon the food through a fine strainer or sieve to smooth the lumps and remove unprocessed parts of produce (this step may or may not be required).
Spoon the puree into single-serving dishes or storage containers; serve the puree to baby. Store it promptly for later use.