S.H.
If this is the way they are eating and will eat, no worries. It is just the "cook" that is getting tired of it. LOL
In kids, their taste buds are still developing as well... and many things are an "acquired" taste... just keep feeding them what they "will" eat... since they are eating healthily... then, here and there offer them other things. It's a gradual thing.
This is just one food phase... others will come up as they get older. LOL
One thing my kids like is "hummus" either with pita or as a dip for ANYTHING. And it's healthy.
If they like things "plain" that is perfectly okay....they are eating. Heck, even some grown-ups don't like different foods and want everything plain and simple and it may be "boring" to us... but that is how they eat.
take heart... it will change, maybe just not yet. And throughout their entire childhood... other preferences will come up. It's okay.
All the best,
Susan