Simmer the shallots in a pan of water for 2-3 mins, then drain and set aside. Season the steaks with a little salt and plenty of crushed peppercorns. Heat half the butter in a pan until sizzling, then cook the steaks for 3 mins on each side for medium or until done to your liking.
Remove the steaks and keep warm. While they rest, add the remaining butter to the pan, throw in the shallots, then sizzle in the sticky pan until starting to brown. Add the balsamic vinegar and bubble for a few mins. Add the wine and boil down until sticky, then add the beef stock and simmer until everything comes together. Spoon the shallots over the steaks and serve withgreen beans and chips.