Subway slang for warming up one's sandwich sub. When the Subway workers are taking someone's order, they tend to slur their words. So, when they ask if you want to heat or toast your sub, they may say "Do you want it toashted?" It is quite common and makes your interactions with them more personal with such quirks, much like your uncle who slaps his knee every time he makes a corny joke.
Kumar: Hello! Thank you for coming to Subway! How may I help you?
Danny: Ah, yes, could I get a footlong Italian BMT on oat?
Kumar: Okey doke. Would you like it toashted?
Danny: Oh yes! I love a nice, warm sub!
When you roast someone and they have no comebacks at all and just standing there, absorbing the screams from the crowd as the roastee, makes a square in the air with his hands, and waves a check in the air.
1: You're ugly!
2: That sounds like a mouthful, i'm sure you used that when you were choking on your dads dick.
Crowd: OOOOOOOOOOOOOOOOOOOOOOOOOOOOOHHHHHHHHHHHHH
an example of someone being Roasted, Toasted, Packaged up, and Posted.