Remove the core and let the cauliflower dry completely. Coarsely chop into florets, then place half of the cauliflower in a food processor and pulse until the cauliflower is small and has the texture of rice or couscous – don't over process or it will get mushy. Set aside and repeat with the remaining cauliflower.
Combine egg and egg whites in a small bowl and beat with a fork. Season with salt.
Heat a large saute pan or wok over medium heat and spray with oil. Add the eggs and cook, turning a few times until set; set aside.
Add the sesame oil and saute onions, scallion whites, peas and carrots and garlic about 3 to 4 minutes, or until soft.
Raise the heat to medium-high. Add the cauliflower "rice" to the saute pan along with soy sauce. Mix, cover and cook approximately 5 to 6 minutes, stirring frequently, until the cauliflower is slightly crispy on the outside but tender on the inside. Add the egg then remove from heat and mix in scallion greens.