This method uses foil to keep the meat juicy while ensuring it "melts" by the end of the cooking process.
Select a rectangular slab of uniform thickness, at least 3.25 cm (1.3 inches) thick. This ensures every part of the meat cooks at the same rate.
Choose a piece with clearly visible, even layers of meat and fat. A good ratio is roughly 50% fat and 50% meat . If it’s too lean, the meat will be dry; if it's over 80% fat, it may be too greasy.