Warm olive oil in a Dutch oven or large heavy-bottomed pot over medium heat. Sauté onions until soft. Add garlic, cumin, chili powder, dried oregano, and garlic powder and cook for an additional 30 seconds.
In a blender, blend chicken stock, chipotle peppers, and tomato paste until smooth. Pour the blended chicken stock mixture, canned tomatoes, and beans into the pot. Add the chicken breasts. Raise heat to high to bring the soup to a boil, then reduce to a simmer and cover. Cook for 20 minutes, or until the chicken pulls apart easily.
Remove chicken to a bowl and use two forks to shred. Return shredded chicken to the pot, add cilantro and lime juice, and stir to combine.
Serve immediately with toppings of your choice.