When everything's ready, Fields rolls camera. The first assistant director bursts Field's bubble again, however, this time citing technical problems. If have that, people will think I actually cook. The director then confers with his crew, and in a moment, they're ready for take two. The moment is in the can without a hitch.
Fields then comes over to talk for a brief moment.
Believe it or not, it's less expensive and more effective to do that stuff later, with opticals, than to bring in stunt men and risk using real fire. Our little blowtorch is all the fire we really need to pull it off. Just then, a crewman walks by with the incinerated veggies. Fields cracks up. It's the height of sci-fi, and you were here to see it.