Fussy eater 101 (if it doesn't work for you, at least it passes the time):
I don't have enough time to be a cafe, plus I like to eat healthy creative meals, so we use the 1 teaspoon rule.
We put one teaspoon of everything on thier plate, they have to finish just one teaspoon, and can have as much as they like of anything else we made until it is gone (that includes desert, which I make on the weekends).
Sometimes there was fussing, but we just gently always repeated, "you only have to eat that one little teaspoon, and you can have as much of whatever else you like".
Now, at this age, they eat quite a wide variety of things, because they learned that appearance doesn't always mean YUCK. There are still some things they don't like, but they know they can always wash down almost anything with milk. (A good skill to learn, because we all end up in situations some day that we have to graciously choke down something we can't stand because someone else was so kind to cook for us or take us out).
NOTE: I always make a wide variety of things to eat, so they never starve, and there is always something that they will like during a dinner. Also, when we go out to eat, or eat at someone else's house where someone superloaded their plates, we tell them they only have to take one bite of the things brought to them.
Good luck
(OH! I forgot, this was rewarding....when they started school, and had school lunches, they came home to tell me, after all of their complaining, that I cook much better than the school does. Had they never eaten my cooking, I would have never heard that!)
I wish I had ideas for getting him to eat other foods, but I do not! 
maybe asparagus!
