Marinate overnight, or at least 1 hour in the refrigerator the first 5 ingredients.
Cook meat over medium heat in a large skillet or wok, if meat is not tender add 1/2 - 1 cup water cover and simmer for 30 minutes or until tender and water is evaporated.
Mix and set aside the next 4 ingredients using either the cornstarch or brown gravy mix, only 1 is required, set aside.
While meat is cooking, cut veggies (to desired size for stir fry) using the first 4 listed and then whatever combination you desire. Keep the veggies separate as cooking times vary.
Remove meat from pan and add oil. Turn up heat to medium high.
Add onions, celery and carrots to pan and cook for 2 - 5 minutes.
Add the rest of the veggies and STIR FRY meaning don't just let them sit, keep them moving in the pan. Cook until tender crisp (fork tender).
Add the gravy mixture and bring to a boil.
Turn off heat as soon as gravy starts to thicken, as veggies will continue to cook (and will get overcooked so make sure they are only tender crisp when adding the gravy mixture)!
*for pepper steak substitute green and red bell peppers for broccoli, approximately 2 cups each and omitting the last 3 listed veggies.
** you can add any veggies you like to this. Just remember some cook quicker than others so add the "harder" veggies first. If you add all the veggies at once some will come out soggy while others will still be hard.