Preheat your oven to 375°F (190°C).
In a large mixing bowl, combine the shredded chicken and buffalo sauce until well coated.
Add coconut milk, steamed cauliflower, carrots, celery, onion, and nutritional yeast to the chicken mixture.
Season with salt and pepper to taste and stir until evenly mixed.
Pour the mixture into a casserole dish and spread it out evenly.
Bake for 25-30 minutes, or until the casserole is bubbly and heated through.
Garnish with chopped green onions before serving. Enjoy warm!