Saute. Add oil (2 tablespoons) to a large pot over medium heat. Once shimmering, add the yellow onion (1 1/2 cup chopped), bell pepper (1 chopped), and jalapeno (1 minced) until softened—about 7 minutes. Add minced garlic (1 tablespoon), taco seasoning (4 tablespoons), oregano (2 teaspoons), and continue to saute for about 2-3 minutes, or until garlic is fragrant.
Simmer. Add salt (1 teaspoon), pepper (1/2 teaspoon), diced tomatoes (14.5-ounce can), salsa (16 ounces), and chicken broth (3 cups), and stir to combine. Add the chicken breast (2), and fully submerge in the cooking liquid. Bring your soup to a boil, then reduce to a simmer and cook for 20-25 minutes--you'll know it's done once the center of your chicken breast reaches an internal temp of 165 F.
Shred chicken + serve. Remove cooked chicken from the soup, set it aside on a plate, and allow it to cool. Once cool enough to handle, shred the chicken into bite-sized pieces and add it back to the soup. Give everything a good stir. Taste and adjust seasoning to your liking. Ladle soup bowls (nutritional information is based on 1/6th of the recipe) and top with suggested toppings. Enjoy!