Use any thin cut of beef--shell, flank, hangar, tenderloin sliced with a grain. Make a chimichurri sauce: the leaves from two or three bundles of flat-leaf parsley go into the food processor with salt, pepper, a few shakes of Tabasco and lots of garlic (we used all the cloves from one head). Process and stream in enough olive oil for a thick sauce consistency, then add distilled white vinegar until it tastes piquant.
Use half the sauce to marinate the beef for an hour or so. Grill the meat, just a few minutes per side for medium rare. Serve with reserved sauce. We dished ours up with grilled tomatoes sprinkled with sauteed garlic, Parmigiano-Reggiano cheese and fresh thyme, along with grilled fresh asparagus and scallions.
