Actually sort of. I mean I guess what you would call a soup. Though the Chinese would just consider that a sauce. The put that shit on everything. Well different sauces. Here’s a random picture of a Chinese school lunch.
https://whatsforschoollunch.blogspot.com/2009/08/china-school-lunch-fish-and-vegetables.html
You see how the veggies are glistening? They’re covered in a sauce made with cornstarch and broth. Even the fish has a layer of sauce on it.
So yeah, a sandwich would be pretty dry. But that’s not really what they’re talking about.
In Chinese food, there’s an insane amount of seasonings that basically go in everything. At a minimum they use something called 5 spice which is a mixture of you guessed it, 5 spices. So the dry they’re referring to is actually seasoning. So something like a subway sandwich with italian dressing, salt, pepper and oregano wouldn’t be dry in the way they’re using it. They’re really just referring to the sandwich being unseasoned. Also, here’s a tip, if you’re going to make a sandwich, season it. Even just adding salt and pepper will make it taste way better.
Well… if you’re in America I’d be cautious about adding anything. Unfortunately, American peanut butter is already heavily seasoned with sugar and salt which makes it a game of over powering the seasonings that are already in American peanut butter. But if you crush your own peanuts with a small amount of salt, as others have said do as the Asians do. Curry powder works great, cumin and as all Asians pretty much do, add some kind of hot sauce (if you can take spicy). But sadly, if you’re looking at a can of jiffy, you’re gonna need a lot of curry powder to overwhelm the salt and sugar content.