coarsely ground 1-lb of beef sirloin with 1-lb chuck. double-ground half of the total batch, then lightly hand mixed with a healthy amount of salt and pepper, 1t. olive oil, 1t. soy sauce, and 1t. white vinegar. formed into 1/3 to 1/2-lb balls/patties (that's right) depressing the top middle of each burger form (to avoid having a meatball instead of a burger, and for even cooking). let the grill heat up for about 30-min, then cooked the burgers for about 3-min per side, placing the sliced gruyere onto the burgers for the last two minutes of cooking. sliced and lightly fried the cut faces of some portuguese sweet rolls in butter until golden brown. slathered some mayonnaise on the rolls with a little ketchup and some dressed greens (olive oil, cider vinegar, salt and pepper). threw some meat on the rolls - burger magic.