Pulse cauliflower florets the bowl of a food processor until it resembles rice, about 2-3 minutes; set aside.
In a small bowl, whisk together soy sauce, sesame oil, and white pepper; set aside.
Heat avocado oil in a large skillet or wok over medium high heat. Add garlic, onion, and mushrooms to the skillet, and cook, stirring, until onions have become translucent, about 3 minutes. Stir in the celery, carrots, bell pepper, and cook, stirring constantly, until vegetables are tender, about 3 more minutes.
Stir in riced cauliflower, green onions and soy sauce mixture. Cook, stirring constantly, until heated through and the cauliflower is tender, about 4 minutes.
Serve immediately, garnished with sesame seeds, if desired.
You can add in protein with this meal (such as ground turkey, or scrambled eggs) OR serve as a side dish.