Place the red beans (rinsed) into a large pan and cover with 5 cups of cold water. Bring to a boil and simmer for 2 1/2 hours. Peel the potato, slice and cut into small pieces. Squeeze the lime juice over the potato and season with salt. Remove the silver skin from the tenderloin. Very carefully remove and discard the seeds from the serrano chilis and finely chop them. Blanch the tomatoes in boiling water for 2 minutes - with a slotted spoon, remove and cool - then peel off skin and discard the seeds. Wash, dry and finely chop the cilantro. Cube the meat into 1 inch cubes. Chop the yolk of the egg into a crumb mixture. Place a large frypan on high heat and add 1 tablespoon of clarified butter. One by one drop the cubes of meat into it. Season generously with salt and black pepper. Sprinkle 1 tablespoon of the flour over the top of the meat and stir. Pour the 2 ounces of chili juice from the can onto the meat. Add the finely chopped peppers. Stir the simmering beans and add 1 cup of cold water. Quickly pass the blade of the knife through two of the tomatoes and add to the meat. Moisten with 1/4 cup of red wine. Stir the meat once again. Dry the lime marinated potato strips on a paper towel and add the meat mixture. Add the peas. Moisten again with 1 ounce of red wine and reduce the heat to low. Mash the beans and beat in the butter and season with one teaspoon of chili powder. Cut the remaining 6 ounces of tomatoes into small pieces and add these to the beans. Pour the meat onto a serving platter and arrange the beans along the side. Sprinkle the chopped egg yolk and cilantro over the top and serve.
A Specialty of La Concha Beach Club at Las Brisas, Acapulco, Mexico with minor changes by Graham Kerr.