Thinly slice the beef across the grain. Place into a bowl. Add half the peanut oil and half the hoisin sauce and stir to coat.

Heat a wok or non-stick frying pan to high heat until hot. Add the beef and stir-fry for 1 minute until it begins to brown, remove and set aside.

Reduce heat to medium-high and add the remaining peanut oil. Add the stir-fry mix and cook for 2 minutes. Add 1 tablespoon of water, cover wok and wait 1 minute. Remove the lid and return the beef to the wok along with any juices. Add the remaining hoisin sauce, stir-fry for 1 minute until vegetables are tender-crisp. Remove from the heat and serve.