Place the cauliflower into the bowl of a food processor fitted with the chopping blade, and pulse about 20 times or until it resembles rice. Set aside.
Heat oil in a saute pan on high heat, and add scallions, garlic and ginger. Saute for about 2 minutes.
Add eggs if using, and mushrooms. Stir well so egg scrambles quickly.
Add cabbage and carrots and combine all ingredients well.
Reduce heat to low, and add the riced cauliflower, soy sauce, hoisin sauce and sesame oil. Stir gently and let the mixture heat through for about 5 minutes
Serve immediately, garnished with chopped cashews.