They may yet eat it. Sometimes cats are just that resistant to change. Maybe you could try mixing a little with their normal wet food. I know I am a little leery of commercial wet food now but cats have a mind of their own and there may not be anything else you can do.
I made a very basic version of this recipe today, to see what my cats thought of it. It was really just chicken with a little rice and olive oil. They ate about half of what I offered, so I think that's a promising start. Even my picky old girl tasted it. I hope they'll still eat it with supplements added.