This trophy does not have to be gotten during the Cook's Recipe for Disaster DLC. The best spot on the game to farm for this trophy is during King Dick's chapter when in the strip club. The mission will start out with around 7 guys in front of you. Just run around until you've gathered all of the goons into a position where the grenade blast will take out all of them (just make sure its not too close to you or you at least have room to run away from it). After they are all dead, 4 more guys will come out of the side doors in the back of the bar...use the same strategy here too and leave the bar as instructed. After finishing this area, you can come back to it at anytime from Dead End and keep up the same pattern for the trophy.