Easiest way is to mix wet and dry as they say above. We have a 5mth old puppy and have fed him burns puppy mixer with naturediet once we moved him off the breeders food. I divide a pack of Naturediet in to 3 (3 days food) and he gets 1/3 of the piece in the morning and the other 2/3rds in the evening his lunch is just dried food although that will be phased out soon

If you don't want to use Naturediet then the James Wellbeloved food is wetter and can be squeezed over the kibble and mixed in.

The puppy wont starve although you can feel that it is going to and will eat when it needs to. If all else fails a little(and I mean a little) tuna, pilchard, sardine may well do the trick