Baking wet dog food to make treats?

My old boy moved to eating strictly wet food, specifically Hill's Science Diet- the ones that are more like a stew, with chunks in liquid. The issue is he always leaves all of the actual wet soup part behind, just eating the meaty chunks, and I hate throwing away any kind of food.

I know it's a thing to dehydrate or mix with flour to make treats, but I only have a mini countertop oven to bake with, and I've read that flour isn't great for dogs. Maybe a dumb question, but has anyone here tried just baking the wet soup part before? Is there something else I could mix the liquid with that's safe for dogs? It has some tiny rice and veggie chunks in it as well, but I don't think it's enough to hold it together.