Let me start with the strange part . Américain préparé is what we call steak tartar here if you can't get it pre-made in a deli or butcher shop you can make it yourself easily, since no cooking is involved. I'll put the recipe here for 1 pound; you can divide the recipe according to need.
1 pound of fatty pure beef mince (not lean) or select a nice piece of fatty meat and have your butcher mince it for you (twice through the machine so it's very fine); 1 small onion or 2 shallots (finely chopped); 2 egg yolks; 1 tablespoon of finely chopped parsley; 1 teaspoon of chopped chives; 1 tablespoon of pickle capers; pepper and salt; 1/2 cup of peanut or sunflower oil.
Stir the egg yolks with a whisk; gently poor the oil in while whisking in the same direction. Once the oil is in you should have something that's a bit like mayonnaise. Add a pinch of salt, a few turns of the pepper mill, the capers, the chives, the parsley and the onions. Now give it a stir with a spoon.
Add the half pound of ground beef and mix it all in so you have a homogeneous mixture. This should make enough to make 5 sandwiches (or more). (Don't cook this--it's supposed to be raw).
Ok , now we have the américain préparé. Let's start making martino's.
Cut your baguette in half and then slice it open. Take out most of the inside of the bread since we want a crunchy sandwich.
On the bottom part of the baguette spread a layer of américain 2-3 ounces.
Cut your tomato slices in half so you have 4 parts per sandwich and put them on.
(Optional) Add 4 slices of gherkin.
In a small glass, mix up 2 parts ketchup for 1 part mustard, or 1 part ketchup for 1 part sweet mustard and put about 3-4 teaspoons worth lengthwise all over your sandwich.
Cover the whole with lettuce.
On the lettuce put 4 salted anchovies (the kind you put on pizzas (usually tinned) not sour pickled ones).
Add a few drops of Tabasco sauce on top.
(Optional) Add half a sliced, hard boiled egg on top of the anchovies.
That's it, all done. This is one of my favorite sandwiches and was happy to share this recipe.