The 19 year old son of our friends has just had his first round of chemotherapy. Recommendations for dinners to deliver?

I like the miso soup idea, you can find powdered 'dashi' at Asian stores. Unlike chicken and beef stock powders, it's very close to the long homemade version. (It's what most mid-class resturants use).
Choosing Miso can be tricky--while most miso soup calls for white miso, I prefer the brown miso. It keeps years in the 'fridge. "MisoMaster" brown miso is a good brand. Very high quality, USA brand. I like it for the salt and earthy taste and it's soothing.

To make the soup, Put a couple of tsps in a bowl..and a bit of the hot dashi over it, and mash with a fork and repeat..then add additions (tofu,re-hydrated wakami seaweed, mushroom slices) and pour more hot broth over it--I use a Pyrex measuring cup in the microwave with dashi powder and water. Very simple.

Here's a great new blog by food blogger/doctor The Merry Gourmet. http://despitecancer.com/tag/sharing-meals/

Thank you everyone! One of the reasons we decided to bring dinners as it will guarantee a big hug each day from someone who loves them. You are all so thoughtful. I'll get out the soup pot, and start some bread!

Matzoh Ball Soup. The most minimalist version: just an extremely flavorful broth (think double stock), maybe a coin or two of carrot, and the matzoh balls.

Another post-chemo classic is Miso Soup. Can have lots of veggies, tofu, or just 'naked' water + miso as a broth. Also, if his appetite is OK, simple comfort foods, on the 4th grader level.

I have such a nice book written by oncologist, it has so many recipes to make before and after chemotherapy or on the morning of the chemotherapy...the book's title is "Eating well Through Cancer" by Holly Clegg & Gerald Miletello, M.D., I will try to share some recipes from it for the boy. i will take pictures in my phone and send you as soon as I can..being a social worker I know, giving time is much more precious than anything else..take a good comedy movie to watch...to lighten up the mood..

I definitely agree that you should find out what they like, and what he'd like to eat. Soups are a very good idea. This roasted carrot soup is healthy, tasty, and it includes ginger (which is good for nausea). http://www.food52.com/recipes/9743_roasted_carrot_soup

And as drabs said: hug them often. I'm hoping for the best.

I second cookie and drbabs. Also, my sister-in-law loved this instant ginger honey tea for nausea when undergoing chemo. I've seen it at Asian supermarkets too.
http://www.amazon.com/Natural-Instant-Caffeine-Sampler-Sachets/dp/B000B8ZA60

Oh my. This is a lot. I remembered a thread about this not too long ago. Here it is:
http://food52.com/hotline/9038-suggestions-for-supper-for-friend-undergoing-chemotherapy

I would make them soup. And find out what they like and make that. And hug them as often as possible.

It may be difficult to feed the parents and the child to the same degree. Mild rice dishes, fresh breads or muffins may be best for the patient. Appetite or lack thereof is strongly dependent on the reaction to treament. I hope the best for your friends.