No concessions are made to children, portion or price-wise (that hamburger, £9.50 and no fries) so it's an expensive treat. Knightsbridge parents (a breed apart, believe me) didn't bat an eyelid. With its Manhattan-ish, Rat-Pack-friendly vibe, Frankie's would make a fantastic supper club. Bring on the Martinis and the pastrami on rye.