Cube chuck roast into 2-3-inch pieces. Add to slow cooker.
Top with remaining ingredients. Cook on low for 5-6 hours.
Remove beef from slow cooker to cool. Once meat is cool enough to handle, shred with two forks or diced into small cubes. Return to slow cooker; mix to combine.
Serve over a bed of lettuce, cauliflower rice, or tortillas.
Nutrition Facts
Per serving: 282 calories, 8g fat, 2g net carbohydrates, 34g protein