Finely dice your Lettuce, and add 2 Tbl spoons to a mixing bowl. Finely dice Shallots and add to bowl with Lettuce. Finely dice Gherkins and add 2 Tbl spoons to the mixing bowl. Add the juice of 1/4 of a Lemon. Add 3 Tbl spoons of Mayo. Add 1 Tbl spoons of Ketchup. Add 2 Tbl spoons of Dijon mustard. Mix everything together and season to taste.