If you're making your riced cauliflower yourself, rice it using a food processor (or grate it by hand).
In a large bowl, mix the beef, pork, garlic powder, salt and pepper.
Put a large pot of water on the stove over high heat. To prepare the cabbage for rolling, lightly boil it whole and peel the leaves off a few at a time. Cut the core out of the cabbage and place in the pot. Bring to a boil and then reduce the heat to a simmer. As the leaves soften, you can peel them off with a spoon or pair of tongs.
In a large skillet over medium-high heat, add a tablespoon of coconut oil. Add the onion and sauté for 3 to 5 minutes until the onion is translucent.
Combine the onion and riced cauliflower with the meat, and mix by hand to incorporate all the ingredients.
Take a cabbage leaf, concave side up with the stem toward you, and place a large spoonful of the meat mixture at the stem end. Then roll forward, fold the sides in and end with the seam down.
Mix the crushed tomatoes and tomato sauce in a bowl. Put about 1 cup in the bottom of the slow cooker. Lay the cabbage rolls in with the seam side down.
Cover with the remaining tomato mixture once the slow cooker is full.
Cook on low for 5 hours.
Serve & enjoy!