For the Enchilada Sauce: Combine all ingredients in blender and blend until smooth. Set aside.
For the Soup: In a large sauce pot, warm the oil over medium heat. Sauté the chopped onions for about 5 minutes, stirring occasionally. Add the minced garlic, oregano, and cumin and cook for another 30 seconds.
When the onions and garlic are soft and fragrant, add the canned tomatoes, maple syrup, enchilada sauce (from earlier), broth, and the salt. Stir well and cook over low-medium heat for about 20 minutes, stirring occasionally.
Add the frozen vegetables and black beans, and cook for 10 more minutes. Taste and adjust seasoning, adding more salt or cayenne as desired.