Instructions
-
Step1In 4-quart slow cooker, layer onion slices. Top with beef, fat side up. Sprinkle generously with salt and pepper.
-
Step2In medium bowl, mix chili sauce, brown sugar and liquid smoke with whisk. Spread over beef.
-
Step3Cover; cook on High heat setting 4 to 5 hours or on Low heat setting 8 to 10 hours.
-
Step4Remove beef from slow cooker; place on cutting board. With 2 forks, shred beef. Using slotted spoon, transfer onion to bowl for serving. Return beef to slow cooker; stir.
-
Step5To serve, spoon beef onto tortillas; top with onion, cheese, avocado, tomatoes and salsa.