My Dom wants me to teach him how to cook. I don't mind teaching him, but I don't know the proper way to go about it while maintaining my submission. "excuse me master but you're about to burn the house down" doesn't quite have the right ring to it.
Lol, I don't see what's wrong with saying this at all, ds. He genuinely wants to learn something from you. So go ahead, instruct him with knowledge and pride in your skills, tell him clearly he's about to burn the house down/knock the pots over/spill the cake mixture if he is. Be respectful as you would expect to be but no need to go overboard when you're instructing, (obviously no need to be bratty), but enjoy this experience. He sounds like a lovely Dom that he wants to do this with you.
If you have this sort of relationship, why not see it as a gentle opportunity for a bit of careful teasing as you're teaching him, and if he feels the need to 'turn the tables' later, well, have fun!