A great farming spot to do this is where you encounter Molotov enemies for the first time, which is in the second story mission called "The Home Fires Burn", taking place in the Bayou. At the start of the mission, make sure you grab a weak pistol and keep it for later. After finding Baka, an enemy will throw a Molotov at you and you see a tutorial prompt on how to use Molotovs. Hide behind cover and one of the enemies on the right will always throw a Molotov at you. It usually takes him 20 seconds to throw it. He will shout "Throwing Molotov" or "Firebomb" or "Fire from the Sky" when he is about to throw it -- that is when you must shoot him with the pistol. It is important you use a low-damage pistol, otherwise your weapon might kill him. If you time it right, he will drop the molotov and burn himself. Run down to the other enemies and let them kill you (do not use checkpoint restart, as it may not track progress properly). Repeat this ten times to get the "Flambé" achievement. If something goes wrong, always let the enemies kill you. There are limited opportunities to get this achievement in the game. If you miss this opportunity, it is recommended you try this during a new game.