Remove the tough outer membrane from the meat. Put the wine, oil, chopped garlic, sliced onion, and parsley in a shallow bowl. Let the meat marinate at least 2 or 3 hours, or better, overnight, in the refrigerator. Turn the meat several times while marinating. Flank steak should be at refrigerator temperature when grilled, so store it until the last minute. Grill it quickly over charcoal. The coals should be hot enough and the grill close enough to the coals to cook the steak to a crusty brown on the outside and red rare in the center in 4 minutes on each side. This is a cut that must not be well done. Brush with the marinade as it cooks and season to taste with salt and pepper.

In the meantime, prepare the bread: Split the loaves the long way. Mix the butter-a lot or little, as you prefer-with the garlic and thyme and spread on each half loaf. Put the loaves together again, wrap in foil, and heat on the back of the grill before you start the steak.

When the steak is ready, remove it to a cutting board and with a very sharp knife cut it in thin diagonal slices. Place on the lengths of French bread. Make open-faced sandwiches or cover with another length of bread, as you choose. Cut crosswise in a convenient size. Serve as an accompaniment to drinks, and provide mustard, barbecue sauce, pickles, chowchow, and the like. For a large party, one person should be assigned to grill the steaks and serve them as fast as they are demanded. This is one of the best and easiest of hors d’oeuvre I know.