I think the recommendation is to cook from frozen but personally I think they are better done after de-frosting. I too just zap them in the microwave on the defrost setting and then 5 minutes on the George Foreman brushed with worcestershire sauce and it does the trick. i think if youcook them from frozen it's very easy to overcook them and they end up chewy and tough.
Thanks for your replies, it just threw me 'cos I used to buy bags of frozen ones from Iceland 10 for £2 but haven't been there for ages so when Sainsburys had them chilled for £1 pack I bought loads and chucked them in the freezer but (now ive got off my fat lazy backside to go and look) it says defrost before cooking, I guess theres nothing in them that can make you ill anyway though so will give them a shot.
And Circes... thanks for the tip of brushing George with worcestershire sauce never thought of that!!