1. Saute the onion, carrot and garlic in a dutch oven with the butter and olive oil until they are soft and the onions are translucent. 2. Add all the remaining ingredients, except the corn tortillas, to the dutch oven and bring to a boil. Once it has reached boiling, turn down the heat and simmer covered for 30 minutes. 3. While the soup is simmering, cut the corn tortillas into 1/4 inch strips and coat lightly with olive oil and salt. 4. Heat the oven to 375 degrees and arrange the tortilla strips in a single layer on a cookie sheet and bake for 15-20 minutes until they are golden brown. 5. Before serving the soup be sure to taste it and add salt and pepper as needed. 6. Top the bowls of soup with some of the tortilla strips and serve. In addition to the tortilla strips, the soup can be garnished with fresh avocados, chopped onions, sour cream or cheese. *To make this recipe even simpler use store bought tortilla chips and skip steps 3 and 4.