Heat olive oil in a large pot. Season the chicken with salt and black pepper, grill then remove and set aside.
In the same pot, add chopped onion, tomato, garlic, spices, bay leaves and cinnamon stick. Add water and broth to cover and simmer for 10 minutes.
Remove the bay leaves and cinnamon stick, then blend the mixture until smooth and pour the sauce back into the pot.
Return the chicken, bay leaves and cinnamon stick to the pot. Add oregano, cumin, salt and black pepper. Bring to a boil, reduce heat and simmer for 20 minutes until the chicken is tender.
Shred the chicken, return it to the pot and mix well with the sauce.
Serve ¼ of chicken birria with 2 heated corn tortillas, 15 g light cheese, ¼ red onion, ¼ avocado, fresh cilantro and lime juice to taste.
