Heat vegetable oil in a pan. Add finely chopped onion and pass until soft for 3-5 minutes. Put the chopped garlic and cook another 30–60 seconds. Add chili powder and cumin and cook for about a minute.
Put the washed beans, water, and oregano. Salt and pepper and cook until almost all the liquid has evaporated.
Remove from heat and knead half the mass with a fork.
In another bowl, mix pumpkin puree, finely chopped chipotle pepper and cilantro. Heat slightly over low heat or in a microwave.
On each cake, put a small amount of pumpkin puree and bean mass. Wrap and serve with salsa, sour cream and grated cheese.