Heat oil in a large stock pot over medium heat. Add the onion and saute for 5 minutes, until translucent. Add the garlic and saute for an additional minute. Stir in the flour, whisking carefully to not get clumps. Cook for an additional minute.
Pour half of the chicken stock and stir until completely combined. Add in the remainder of the chicken stock, and stir to combine. Immediately add in the chicken, enchilada sauce, black beans, tomatoes, green chilies, corn, salt, and cumin, and stir until combined. Continue stirring occasionally until the mixture reaches a simmer. Reduce heat to medium-low and let it simmer for 3 minutes, stirring occasionally so that it does not stick to the bottom of the pan. Finally, add the cheese.
Serve warm soup with desired toppings
Recipe by The Gingham Apron at https://www.theginghamapron.com/chicken-enchilada-soup-2/