In a 3. 5 to 4-quart slow cooker, combine the thawed vegetarian ground meat, rinsed pinto beans, undrained diced tomatoes and green chiles, salsa, chopped onion, and minced garlic.
Stir everything together.
Cover the slow cooker and cook on the LOW setting for 4 to 6 hours, until the flavors have melded and the mixture is heated through.
To serve, warm the tortillas. Spoon the filling evenly among them and top with shredded Monterey Jack cheese, lettuce, and a dollop of sour cream, if using.
Fold into tacos or roll into burritos and enjoy immediately.