Some stew recipes call for adding the meat and most veggies all at once and then pressure cooking. This makes for quick and easy dump and go recipes.  However if the veggies cook too long this can result in vegetables that are soft and mushy. One easy way to help with this is to cut the vegetables into bigger pieces if they are being added with the meat. Other stew recipes call for pressure cooking the meat and broth, releasing the pressure, adding the vegetables and pressure cooking again. This results in vegetables which are firmer, since they don't cook under pressure for as long. But this is a little more involved and doesn't allow as much of hands off cooking time. So which type of stew you decide to make depends on how much time you have and how picky your are about the texture of stew vegetables.