Preheat oven to 375 F and spray large 9×13 baking dish with cooking spray. Set aside.
Preheat large skillet on medium heat and add oil. Add onion and bell pepper, cook for 5 minutes, stirring occasionally. Add carrots and celery, cook for another 5 minutes, stirring occasionally.
Add cauliflower rice and cook until heated through. Transfer to prepared baking dish along with chicken, rice, mayo, hot sauce and chicken broth. Stir to combine and level with spatula.
Sprinkle evenly with cheese, tightly cover and bake for 40 minutes or until rice is cooked.
Remove from the oven and let stand for 5 minutes. Garnish with green onion, avocado and blue cheese crumbles. Cut into 8 slices and serve hot. You can add other toppings like healthy ranch, jalapenos and more hot sauce.
Notes
Store: Refrigerate in an airtight container for up to 5 days.
Freeze: Freeze leftovers in an airtight container for up to 3 months. Thaw in the fridge overnight.