Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1      pound         Ground beef for the best quality
   2                    Egg yolks
                        Salt and Pepper
   1      medium        Onion chopped very thiny
   8                    Anchovies
   1                    Lemon
                        Butter
                        Mustard
                        Chiles serranos chopped
   8                    Bread slices for to make sandwiches

Preparation:

Mix the meat with the egg yolks, salt and pepper, add olive oil as needed for to be a soft dough. In the bread slices put the things in this order: butter, mustard, meat, onion finely chopped, 3 or 4 lemon drops, and one anchovie. Add chiles serranos chopped if desire.