Your yorkie is over a year old now, right? A few things you could try would be to put his food in a saucer instead of a bowl; put a little cottage cheese on the side if he likes it to get him "primed"; try different dog food brands, because he just may not like what he's getting.
Also, you could boil a bit of white meat chicken and put a little of it on one side of his new plate and some dry dog food on the other side. Sometimes after eating the chicken, if he's still hungry, he will dive into the dry food next. Good luck.