An authentic Florentine T-bone steak is cut from a Chianina cow and aged for about a week. Though Chianina beef is lean, it's prized for its rich flavor and balanced texture (perhaps due to the Chianina's grazing locale in Siena, Arezzo and environs). Since we do not breed pure Chianina cattle in the United States, purchase the best steak you can find. The meat should be 1 to 1 1/2 inches thick and weigh 1 1/4 to 1 3/4 pounds. Ask for a porterhouse steak as this is the larger of the T-bone steaks. It's essential that the steak is grilled over very high heat (charcoal is best) but a cast-iron grill pan works, too...