What about letting him 'help' with meal prep? My girls are way happier eating food they've prepared with us. They also love to pick veggies out of the garden that they've helped grow (although it's a very small garden and that only works during summer months).
I have some very strong food dislikes and am not very adventurous when it comes to trying new things. My parents put the food in my mouth but I refused to swallow it. It's all about power. And if you make it an issue, it becomes one. I try to balance respecting their dislikes with getting them to try new things. We usually have a healthyish dessert, like a homemade cookie or a granola bar or fruit that only gets served if they've eaten what I've served them. I'm not concerned with a clean plate, but all veggies have to be gone and a decent attempt to eat whatever else has to be made.
I try to have all their daytime choices as healthy as possible, loads of fruit and at least one veggie serving, so that I know they've eaten well through the day. (Daycare and school eating has never been a problem). This way, I don't stress about how much dinner gets eaten. They might be too tired to eat, or full from a late snack at daycare. At this age though, if they don't eat what I've served for dinner, they don't get anything else, because I don't serve them things I know they really don't like. That said, I often am making separate meals for them and DH and I, because we'll eat spicier foods or whatever. That's kind of a pain.
We always eat breakfast and dinner together, and lunch if we are home. I think that helps too.
