Preheat oven to 350 degrees F. In a heavy-bottomed saucepan over medium-high heat, heat the oil to 325 degrees F (or until hot enough to sizzle when a breadcrumb is dropped in). DO NOT ALLOW OIL TO SMOKE!
In a stand mixer fitted with a paddle, mix together the sausage meat, fresh herbs, and 1 whole egg. Mix together until softened and pliable. Take hard-boiled eggs and wrap sausage mixture around completely covering the egg.
In preparation for breading, prepare the following: Season flour by adding salt and pepper in a shallow dish. Take remaining beaten egg and mix with milk in another shallow dish. Put panko breadcrumbs in a third shallow dish.
First roll the sausage-covered egg into the seasoned flour. Shake off excess flour and move to the beaten egg mixture and cover completely with egg. Remove any excess, then roll in breadcrumbs. Drop immediately into hot oil and cook until golden brown. Remove, place on sheet pan, and place in oven for approximately 10 to12 minutes or until sausage meat is cooked.
For sauce, mix mayonnaise, mustard and lemon juice together and serve with scotch eggs.