Stir together all ingredients except fresh parsley in a 7-8 quart slow cooker, making sure it's well combined.
Cook on low for 7-8 hours or high for 3.5-4 hours, or until beef is fully cooked.
Stir in fresh parsley.
You can use frozen cauliflower rice or pulse raw cauliflower florets in your food processor until it resembles the texture of rice. Regular rice can also be used if you are not following a grain-free diet. Use 1 cup of uncooked rice and add 2 cups of chicken broth, veggie broth, or water to the casserole before cooking.
Freeze leftovers in an airtight container for up to 6 months.
If you are using a very lean ground beef, I recommend adding just a little bit of liquid to the casserole- just a half cup of water, chicken broth, or veggie broth.
Optional: add mozzarella cheese! Just add it on top of the casserole after its done cooking and place the cover back on, and let it melt for a few minutes before serving.
The provided nutrition information does not include any added sodium from seasoning to taste, any optional ingredients, and it does not take brands into account. Feel free to calculate it yourself using this calculator or by adding the recipe to Yummly.