Combine chili powder, cumin, oregano and kosher salt in a small bowl.

Sprinkle the chicken with 1 teaspoon of the seasoning mixture.

In a large heavy pot brown both sides of the chicken over medium-high heat. Remove the chicken from the pot and reserve.

To the same pot, add 1 cup chopped onion, carrots, garlic and remaining seasoning mixture. Cook until the vegetables are just tender, about 10 minutes.

Return the reserved chicken to the pot along with the chipotle peppers in adobe sauce, chicken bouillon, water and bay leaves.

Bring to a boil. Reduce heat to medium and simmer for 1 hour.

Remove the chicken pieces from the pot; let cool and then shred the chicken, discarding the skin and bones. (makes about 3 cups shredded chicken)

Remove the bay leaves from the pot and discard them.

Using an immersion blender, puree the sauce and vegetables that are in the pot until smooth. (makes about 4 cups sauce)

Heat a large nonstick skillet over medium-high heat.

Dip the corn tortillas into the sauce to coat both sides and place the tortillas, in batches, in the heated skillet. Place chicken (about 1/4 cup per tortilla), remaining chopped onion and shredded mozzarella cheese on top of the tortilla. Fold in half and cook, turning once.

Repeat with the remaining tortillas and filling ingredients.

Serve the tacos, topped with additional cilantro leaves and chopped onion, if desired, with the remaining sauce for dipping.