spanish onion, sliced
Cut steak into 4 pieces; rub with salt and pepper.
Heat butter in large frying-pan until hot but not brown.
Brown meat on both sides; remove to platter.
Add sliced onions to frying-pan and fry lightly; remove from pan.
Add water to frying-pan, scraping pan to loosen any bits of beef.
Return meat to pan; cover with onion slices.
Add vinegar, mustard, bay leaf and cloves.
Cover and cook slowly 1 1/2 hours or until tender, turning every 1/2 hour.
Place steaks on serving platter.
Remove bay leaf and cloves and place onions on platter.
Granish each steak with 1 spiced onion and 3 pimiento strips.