Brown the meat and onions in the oil. Add the tomato sauce, beer, beef stock, chilies, cumin, garlic, black pepper, and 2 Tbsp chili powder. Simmer the chili over a low heat for 2 hours until the meat is tender.
To thicken, make a thin paste of the masa and water. Quickly stir this into the chili – if done too slowly, it will lump.
Add the remaining chili powder and paprika. Simmer for an additional 15 minutes. Remove the Jalapenos and serve.