1

Heat the oil in a medium frying pan over medium-high heat. Add brown onion and garlic; sauté for 5 minutes or until softened and lightly browned. Spoon onion mixture into the bottom of a slow cooker. Top with chicken.

2

In a medium bowl, stir together tomatoes, chipotle, cumin, oregano, paprika, bay leaves and 1 tsp salt. Pour the mixture over the chicken. Cover and cook on Low for 3 to 4 hours or until the chicken is tender.

3

Meanwhile, combine vinegar and ¾ cup water in a small saucepan; bring to a boil. Add red onion and return the liquid to a boil. Immediately remove pan from the heat and let it stand until the mixture cools to room temperature. Drain the onions and place in a bowl; stir in ¼ tsp salt.

4

When the chicken is tender, shred the meat in the slow cooker, stirring it with the sauce to combine. Divide the chicken, pickled onions, avocado, cheese, and coriander evenly over the tortillas.