You can use the spice paste mentioned above for this soup. The ingredients listed will yield about ½ cup of spice paste. You can store the leftover paste in the fridge and use it for any stir fry or Asian dishes.
We used leftover turkey meat instead of chicken, but you can easily swap turkey for chicken breasts.
Also, if you're not a big fan of fish sauce, you can just season the soup with salt. But i promise, the soup does not taste fishy at all. the fish sauce just add some saltiness to the soup.
For the red curry paste, sambal oelek and tomato paste - you can add as much or as little as you like. It's up to you how spicy you want your soup to be.
I also had kaffir lime leaves in the fridge so i added a few leaves to the soup. but this is not essential.