Combine all the ingredients and beef except for the cornstarch in a bowl and marinate for at least 1 hour.
While this marinates, wash and prep all the veggies.
Before cooking, transfer the beef to another plate to remove excess liquid and to come to room temp for about an hour.
Coat each piece of beef in cornstarch. Heat a pan on medium high or high, then brown the meat on all sides in about 2-4 batches depending on the size of your pan.
Once you have cooked all your beef, add them into a pan with the vegetables over medium-low heat, and stir for about 2 minutes.
Plate the veggies and beef. Add some Maggi to salt to taste.
