Pour olive oil into bottom of casserole dish and add chicken breasts to dish. Coat with olive oil (add more if necessary) and bake at 350°F (180°C) for about 1 hour, until the chicken is no longer pink inside and the juices run clear. Set aside to cool slightly before slicing and shredding.
Heat oil in a large dutch oven or other large pot.
Sauté onions and garlic for about 5 minutes at medium-high heat.
Add tomatoes, corn, beans, salsa and chicken broth. Stir until combined.
Add taco seasoning and shredded chicken. Simmer for 15 -20 minutes — or until heated through.
Serve with shredded cheese, sour cream, tortilla chips, and any of your other favorite taco toppings