My 11mth old DS is exactly the same, particularly with mushier food, like fish pie or shepherds pie. Any veg sticks, he takes much longer over!
I agree with broquemum - it requires more effort to feed themselves, so I am now giving finger foods much more. My DS definitely starts throwing food on the floor/pushing it around his tray once he's had enough (although at this point, he will still take spooned food as though there is no tomorrow!).
I try to give roughly the portions of jarred food (even though I cook myself) and lots of veg (as I know he gets plenty of protein).
Also, I try to make sure that he takes his time, so he gets the feeling of being full.
I even have to 'monitor' his food - he will literally pick up veg bits I put in front of him, stuff them all his cheeks at once and then find it difficult to chew . So, I have to put a bit out, let him eat it, then another bit out, he eats that bit.
Crikey, reading all of this back, I look like a mean mummy! He definitely eats well and is often described as chubby/good size etc etc, but some babies do just eat and eat and eat. I think if they do eat fast, the recognition they are full might happen too late!
PS funny how these are all boys ...