It’s totally possible to make this dish using frozen veggies. To make sure they don’t come out soggy and to ensure that the dish doesn’t lose its quality I recommend that you DONT let them thaw before you cook them. They should go into your skillet straight from the freezer. Also, make sure that your stir-fry is on a medium-high setting (using a high setting will make a BIG difference and is the best way to avoid soggy veggies).