This achievement can be unlocked by completing the "campaign"with 3 characters
After every level you can see the objectives the roast has, in order to get them you'll have to get a little lucky that A: you get the right sentences for your roast and B: your AI doesn't steal half of them away in his turn.
Overall, all you can do is just try a level over and over until you get it, which is probably not the answer you where hoping for.
On a positive note, you don't have to get all challenges in one go. 2 tricky challenges and you can win the game completing one of them? Great, now on your next attempt that won't be an issue and there is one less challenge to plague your mind
Good Luck and happy hunting