Restaurant manager here. Essentially what the chef requests the servers to recommend will be something that he/she got a good deal on, or something that if they don't sell it that day, will have to be thrown out soon. That's not to say it's not fresh (every city's health department has different shelf lives for various products), but if we ran sea bass on the menu the previous evening and it didn't sell as well as predicted, it might be run at a lower price the next night in order to move the product.

If you want the server's actual recommendation, ask what his/her favorite thing on the menu is AFTER having them tell you about the chef's rec or whatever it's called at that particular restaurant. If they really reiterate the chef's special, then it is likely to be very good because the server knows his/her tips ride on the suggestion often times.

Chris