I've just made this chowder for dinner and my son loves it - so I'd recommend it for kids. It's from Jamie Oliver's book, Jamie's 30 Minutes Meals.
It was very easy, quick and simple and I managed to stick it all on whilst seeing to a baby. Just watch out for bones when serving it to little children. I even left out the prawns and it was still super tasty. I will be definitely making it again, but I think the potatoes could do with a little extra time. Here's Jamie's recipe: