Trim fat from beef. Sprinkle beef with salt and peppercorns. In large heavy skillet brown brisket on both sides in hot oil. Remove beef. Add onions to skillet. Cook and stir until tender. Add brisket to skillet; add tomatoes, broth, Worcestershire, and fines herbes. Bring to boiling; reduce heat. Spoon some of onion mixture over brisket. Simmer, covered, for 3 hours, or until brisket is tender.
To serve, remove brisket from skillet; let stand 10 minutes. Meanwhile, skim fat from sauce in skillet. Stir in cream, vermouth, and vodka. Bring just to boiling. Remove from heat. Slice brisket; top with olives. Serve with sauce. Makes 8 servings.