I've found that getting my son (who is about the same age) involved in cooking has helped. I ask him to choose from certain ingredients & give him a job to help prepare the meal. Obviously you can't do this all the time but where possible it creates a but of excitement about eating.

I have heard that at this age as long as your child eats something that's enough. They will eat as much as they need when they need. But I also eat healthy & would like my kids eating the same so it can become a battle.

I found one handed cooks have some good recipes for fussy eaters too.