Cut tortillas, first in half, then crosswise into 1/4 inch strips.
Heat 1 tablespoon of oil in a large pot over medium heat, until very hot but not smoking. Add in the tortilla strips and sauté until golden brown and crisp, about 4-5 minutes, stir often. Remove from pot onto paper towels; set aside.
Add the remaining 2 teaspoons of oil to pot and cook the onions for 5 minutes, stir often.
Add in the garlic and cook for only 30 seconds before adding in the broth, tomatoes, sweet potatoes, and chipotle pepper; bring to a boil. Lower heat and simmer for 10 minutes.
While simmering, cut the zucchini into 1/2 inch pieces.
Rinse the fish and dry with paper towels, then cut into 1 inch pieces.
After broth mixture has simmered for 10 minutes add in the zucchini and salt, let simmer another 5 minutes.
Stir in the halibut pieces being careful not to break it up. Simmer until fish flaked easily with a fork, about 5 minutes. Stir only once and very gently.
Serve 2 cups soup topped with cilantro and tortilla strips.