To prepare the Tex-Mex seasoning, place the chili powder, ground cumin, ground coriander, garlic powder, smoked paprika, fine sea salt, and black pepper in a medium-sized bowl and stir to combine. Transfer the mixture to an airtight storage container and store it in a cool, dry place for up to 6 months.

Place a large, high-sided skillet or saucepan over medium heat and add the olive oil, garlic, onion, and red bell pepper. Sprinkle over two tablespoons of the Tex-Mex seasoning and stir to combine. Cook for 4-5 minutes, stirring frequently until the vegetables start to develop some color and are crisp-tender.

Add the tomatoes, black beans, bay leaves, and chicken stock/broth to the pan and stir to combine. Add the chicken breasts to the pan and push down so they are completely submerged in the liquid.

Increase the heat to medium-high and bring to a rapid boil, then immediately reduce the heat to just below medium. Cover the pan loosely with a lid and simmer for 35-40 minutes, or until the chicken is cooked through. Shred the chicken with two forks. You can do this directly in the pan, or remove it first and return the shredded chicken to the pan.

Sir the corn and fresh lime juice into the soup and simmer for 5-10 minutes until heated through. Remove the soup from the heat and discard the bay leaves. Taste and adjust seasonings as desired.

Ladle soup into bowls and serve immediately topped with diced avocado, fresh cilantro, and lime wedges for squeezing. Enjoy!