Bring a large pot of salted water to a boil. Cook the short pasta until just al dente according to the package directions, reserve about 1/2 cup of pasta water, and drain.

Heat the olive oil in a large skillet over medium-high heat. Add the cubed chicken and taco seasoning, arranging the chicken in a single layer, and cook for approximately 5 to 7 minutes until browned and cooked through to 165°F internally.

If using onion and garlic, add them to the skillet and sauté briefly until fragrant and softened. Keep the chicken in the pan if there is room, or remove it temporarily if needed to prevent overcrowding.

Stir in the undrained tomatoes with green chiles, rinsed black beans, drained corn, and water or low-sodium chicken broth. Simmer for 5 to 8 minutes so the vegetables, beans, and taco seasoning combine.

Add the drained pasta and cooked chicken to the skillet, stirring until everything is evenly coated. If the mixture seems too thick, add a little of the reserved pasta water until it reaches your preferred consistency.

Sprinkle the shredded cheese over the pasta, cover the skillet briefly, and heat over low heat or off the heat until the cheese melts. Finish with cilantro, green onions, sour cream, avocado, or lime if desired.