...is not the right question to ask someone the first time you try weaning them off red met.
"Oh, you want to know how this burger tastes? Like someone sucked every ounce of goodness directly out of it!"
You don't want them to mentally compare this heart-friendly alternative to the last burger they had. That's just asking to lose. In fact, you don't want them to think about the meal at all. You just make them eat another one the next few times you make burgers. And then, without realizing it, THAT is what a burger has now become to them. They'll enjoy it without remembering what the comparison is.
The second greatest gift God has ever given the world is a short memory.