Stir together the first four ingredients in a small bowl to make the sauce. Set aside.
Heat half the peanut oil in a wok over medium high heat. Cook the shrimp for about 3 minutes (until opaque) and remove them from the wok.
Heat the remaining peanut oil and add the vegetables, cooking for 2 minutes (until crisp tender). Remove the vegetables and set aside.
Add the sauce to the wok and cook for a minute to thicken, stirring constantly. Then add the shrimp and the vegetable mixture to the wok and heat through for a minute, stirring to cover with the sauce. Serve over brown rice.