Heat the oil in a large skillet over medium heat. Cook the garlic, onion, veggie burger crumbles if using, and red pepper flakes until the onion is soft. Add the chili powder and cumin and cook for an additional 2 minutes, or until fragrant.
Place in a slow cooker with the remaining ingredients, stirring to combine. Cover and cook on low for 6 to 8 hours.
Servings: 6 to 8