Beef & Lentils
Both my boys will love this but they wouldn't always have.
It took me years to get them to enjoy lentils. I think the gateway for Max was via dahl. He had a try one time and loved it. From there it was small steps to appreciating lentils.
For Joe it was via a stew that was soup consistency. Being able to eat it out of a bowl with a spoon was what sold him on trying them with the view to attempting to like them.
If my boys don't like something I serve it again and again. I also rebrand and repackage it. Often foods are more palatable/more exciting/more comforting looking if offered one way rather than another.