Gather all your ingredients and tools, including a large heavy-bottomed pot, a sharp chef's knife, and a cutting board. This keeps the process smooth and organized.
Dice the onion and mince the garlic, filling your kitchen with a fragrant, savory aroma as they begin to soften in a splash of oil over medium heat for about 5 minutes.
Add the chicken breasts to the pot and cook until they develop a light golden color, about 7 minutes, stirring occasionally to prevent sticking.
Pour in the chicken broth and stir in the diced or crushed tomatoes, then bring the mixture to a gentle simmer, allowing it to cook for 20 minutes until the chicken is cooked through and tender.
Remove the chicken breasts from the pot, shred them with two forks, and return the shredded chicken to the soup, stirring to combine.
Stir in the thawed corn and drained black beans, then continue simmering for another 10 minutes to let all flavors meld together.
Add cumin, salt, and pepper to taste, and squeeze in fresh lime juice for brightness. Taste and adjust seasonings as needed.
Chop the cilantro finely and sprinkle over the soup just before serving for a fresh, herbal aroma.
Ladle the hot, fragrant soup into bowls, garnished with extra cilantro and lime wedges if desired. Serve immediately for a comforting, lively meal.