Place chicken in a saucepan over medium heat covered by 1 inch water. Add smashed garlic, whole cloves, and a bay leaf. Simmer 20-30 minutes until the meat pulls apart easily.
While the chicken cooks, add tomatoes to a pan over medium-high heat and blacken on all sides, about 6-8 minutes.
Blend the tomatoes with chipotle peppers, chicken stock, cumin, and nutmeg until smooth.
In a large skillet, cook onions, minced garlic and chorizo over medium heat until softened and rendered, about 10 minutes.
While chorizo cooks, remove the cooked chicken from the water and shred with two forks.
Add the shredded lettuce to the chorizo mixture and saute a few more minutes.
Add blended tomato sauce and shredded chicken to the skillet and cook stirring until any excess liquid has evaporated, about 10 minutes. Salt and Pepper to taste.