Most Joy of Cooking recipes call for browning of meat, then removing the meat, and sautéing vegetables, until they're soft, though occasionally it's the reverse.
Does it make a difference? If so, what is it? What is the preferred order for a "new" recipe?
Generally, browning meat is done at high heat, with a preheated pan well over 400°F, and will leave a bunch of tasty brown stuff (fond) stuck to the bottom of the pan. Vegetables contain a lot of water, which will dissolve the fond off the bottom of the pan, bringing its flavor in to the dish.
If you did it in the other order, you'd have maybe have some fond from the vegetables (depends on how long you cook them and how hot), which would burn as you brought them pan to temperature to brown meat.
Meat first - adds some of the meat fat to the pan, and adds flavors from the meat to the pan, which carries them onto the vegetables.
Other direction - veggies don't pick up meat flavor, oil or butter has to provide all the fat for the veggies to sauté in.
Preferred - whatever you prefer, you're creating the recipe, or try it both ways and see what you like better for that recipe.
