In a heavy skillet (I used a cast iron one), fry the bacon until crispy on medium high heat. Remove the bacon and set aside. Chop into small pieces when cooled.
Meanwhile, add to the bacon grease the onion; saute until soft and slightly browned.
Add the chili powder and cayenne pepper; stir to coat the onions.
Add the beans and chicken stock. Use a potato masher to mash the beans to desired texture, then stir to incorporate with the liquid.
Continue heating until heated through. If there is too much liquid, continue heating until some of the liquid has evaporated, until you reach the desired consistency, stirring frequently.
Stir in cilantro, chopped bacon, and season with salt and pepper to taste. Serve immediately.