Cook the rice according to the instructions on the packet. Meanwhile, heat the oil in a large pan or wok over a medium-high heat and add the stir-fry mix and peppers. Cook for 3 minutes, stirring continuously, then add the garlic and cook for another 1 minute.
Stir in the sauce and cook for a further 2 minutes. Stir through the peanuts, then serve with the rice.