My DS is almost 7 months and eating food is not on his high list of priorities either lol.
As my DS is now formula fed I too was worried about iron stores etc.
He just isn't really interested.
We've tried rice cereal, some veggies , fruit and finger food and he's just not that keen.
He doesn't wake through the night so I'm not particularly worried that's he's hungry I just try a little bit everyday.
I'm sure he'll get the hang of it soon I was just expecting him to be like DD and just scoff it down.