Peel the shrimp and cut the sausage into small pieces.
Heat oil in a non-stick skillet. Cook the sausage until it turns golden brown, then set it aside.
In the same skillet, sauté the onions for 2-3 minutes until they become fragrant. Add the chopped bell peppers and celery, cooking until they are soft. Stir in the minced garlic, riced cauliflower, salt, black pepper, and Cajun seasoning. Cook for a few minutes.
Pour in the diced tomatoes and chicken broth, then add the shrimp. Let it simmer until the liquid reduces and the mixture thickens. Return the sausage to the skillet and simmer for an additional minute.
Remove from heat, adjust the salt and pepper if needed, and serve immediately.