Preheat large skillet on low-medium heat and coat with sesame seed oil. Add cauliflower and bell peppers, cover with a lid and cook for 8 minutes, stirring every few minutes.
In a small bowl, whisk Sauce ingredients and pour into skillet. Stir to coat veggies and cook a few more minutes until sauce has thickened. Stir again, sprinkle with green onions and sesame seeds. Serve hot with meat of choice, or over pasta, quinoa or brown rice.