1. Preheat your oven to 350 F. Place the cauliflower onto a baking sheet and spread it out thinly. Bake for 10 minutes until the cauliflower has defrosted and is heated through. Set it aside.
2. Dice the onion, pepper, and celery. Mince the garlic. Add salt, pepper, oregano, and red pepper flakes if desired.
3. In a pan, cook the ground sausage completely. Drain any extra fat if desired. Add the vegetables and cook until tender, about 5-6 minutes. Add in the garlic and cook an additional minute. Fold the cauliflower rice into the mixture and set aside.
4. If adding shrimp, heat a frying pan and add the butter. Toss the shrimp into the butter and saute until pink and cooked. Season with salt and pepper. Place the dirty rice in a bowl and top with your shrimp. Garnish with a bit of parsley and enjoy.