Begin with one cup of good mayo -- I use Hellman's. Add the juice of half a lemon, two cloves of crushed garlic, about a quarter of an inch of anchovy paste (or a couple of anchovy filets that you chop finely) and freshly ground black pepper. Mix it all together to amalgamate it well, then stir in about half a cup of freshly grated parmesan cheese and some black pepper. Then set it aside to allow the flavours to marry.
To build the sandwich, start with two thick slices of crusty bread and coat them generously with the dressing. Top one of the slices with some sliced hard cooked egg and season with freshly ground pepper. Toss the romaine lettuce in enough of the dressing to coat well and layer generously over the egg slices. At this point, you can add another layer of sliced egg or not, depending on how packed you like your sandwiches. My personal habit is to have only one layer of egg slices though I tend to slice the egg a bit on the thick side. Top with the second slice of bread, dressing side down and indulge!! Yummmmmm!!!