I had some leftover crockpot chicken and a hungry husband, so I tried this fairly quick recipe for Tom Kha Gai. It has a lot of ingredients and I didn't have all of them but some of the swaps listed in the comments were helpful.
I added some yellow squash from the garden since I had it. I didn't have fresh lemongrass so I used some freeze dried I picked up. I don't know that I would do that again unless I put it in something so I could remove it between cooking and eating. I thought the soup had a little too much fish sauce (as you can see from the color) but otherwise, it was really good and we would have it again (although he was careful to tell me "not ALL the time, just every once in a while.")