In a large skillet, brown ground beef and the onion together over medium heat, crumbling the ground beef as it cooks. Once no pink remains, stir in the taco seasoning and add the riced cauliflower and can of rotel. Cook until rice cauliflower is tender and most of the water released from the cauliflower rice has been absorbed.
Once the mixture has been heated through, sprinkle shredded cheese over the top and allow it to melt.
To serve, spoon into tortillas or serve over a salad. Serve it with additional cheese, sour cream, avocado, cilantro, hot sauce, salsa, etc. to help satisfy your family and add to your plate as your macros allow!