To prepare the Tex-Mex seasoning mix, combine all ingredients in a medium-sized bowl and stir to combine. Transfer to an airtight storage container and store in a cool, dry place for up to 6 months.

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

Add fire-roasted tomatoes, black beans, bay leaves, and chicken broth and stir to combine. Nestle the chicken breasts into the skillet so they are completely submerged in the liquid.

Increase heat to medium-high and bring to a rapid boil, then immediately reduce heat to just below medium. Cover skillet loosely with a lid and simmer for 35-40 minutes, or until the chicken is cooked through and shreds easily with two forks.

Stir in corn and fresh lime juice and simmer until heated through, approximately 5-10 minutes. Remove from heat and discard bay leaves. Taste and adjust seasonings, as desired, and serve immediately topped with diced avocado, fresh cilantro, and lime wedges for squeezing. Enjoy!