3 the greatest burger Recipes

sherry wine vinegar, olive oil, dijon mustard, worcestershire sauce, ketchup (we used heinz), chopped fresh chives, chopped fresh tarragon, olive oil, shallots, finely diced, garlic cloves, crushed, salt & freshly ground black pepper, crushed red pepper flakes (optional), freshly ground beef chuck (preferably prime grade), chopped italian parsley, dijon mustard, worcestershire sauce, salt, fresh ground black pepper, egg, beaten to blend, bacon, gruyere cheese, frozen foie gras (we didn tsp use), black truffle (didn tsp use, way too pricey), brioche hamburger buns, split in half

butter or 4 tbsp margarine, onion, chopped, mushrooms, chopped, ground sirloin, salt, fresh ground black pepper, a-1 steak sauce, flour (for dredging), olive oil (preferably extra-virgin), kaiser rolls, lightly toasted, cheese , of your choice (optional), sour cream (optional)