Heat a LARGE (12 quart preferably) pot over medium high heat and add the vegetable oil. Once hot, add the onions and spices and saute until onions are soft and translucent, about 5 minutes.
In a separate bowl combine the Masa harina with 4 cups of chicken broth and whisk until combined. Pour mixture into the large pot, and stir constantly, cooking, for 2-3 minutes. Mixture will become thick.
Pour in the remaining chicken broth, enchilada sauce and crushed tomatoes, stir and bring to a boil.
Add the cubed Velveeta cheese, and stir until melted. Stir in the shredded chicken.
Serve topped with sour cream and tortilla strips. Enjoy!