Monte Cristo Sandwich
On a work surface, lay out 2 slices of bread and spread with mayonnaise. Top each slice with the 1 slice of Gouda and 1 slice of turkey each. Put the third slice of bread on top of one stack, and flip the remaining stack on top, cheese-side down, to make a triple-decker sandwich.
Using a knife, cut the crusts off the sandwich (this helps to pinch and seal the ends). Wrap the sandwich tightly with plastic wrap and refrigerate for at least 30 minutes and up to 6 hours. (Wrapping the sandwich in plastic wrap, compacts it, and prevents the egg batter from seeping in.)
Combine the eggs and milk in a bowl. Heat the oil and butter in a skillet over medium-high heat. Unwrap the sandwich and dip it in the egg batter, to coat evenly. Gently place it in the skillet, and fry, turning once, until golden brown and hot, about 5 minutes total.
Professional Recipe: This recipe was provided by a chef, restaurant or culinary professional and makes a large quantity. The Food Network Kitchens chefs have not tested this recipe in the proportions indicated and therefore cannot make any representation as to the results.