I've got 5 stars in s4 ep15 with only 2 slots. I used fast flo and norbert (prune soufflé recipe) as norbert appears the most times in that level and you get double tips. I've only got 4 stars in s4 ep14 though. I keep messing it up. Also when I use fast flo there is a couple of orders where the green sauce gets put on the…
Just a tip.. Table steaks season 3 episode 15 if you use the fast flo VIP then she appears 4 times. So extra fame and extra chances of gold. Also if you have second prep slot open and use another prep recipe with the fast flo one that character will also appear 4 times. So even more fame can be accumulated.