The longer John takes to eat breakfast, the more impatient Sherlock gets. A bowl of cereal has him threatening to shoot more holes in the wall, buttered toast with jam has him threatening to shoot a hole in John and on the single occasion that John cooked himself a morning fry-up, he had turned around from the oven to find that Sherlock had already left the flat and taken a taxi to the crime scene.
Sherlock, on the other hand, is a bloody nightmare when it comes to anything involving him and food and him eating food. Despite his insistence that he really can get by on coffee and nicotine patches alone, his flatmate unfortunately happens to be a rather competent doctor and knows otherwise. John is quite willing to stand over him all day as Sherlock harrumphs and glares and oozes resentment if it means that the detective will eat a decent meal for once.
Sometimes John gets desperate and calls on Mrs. Hudson to bring a cosy equilibrium to the scene. She is the only person he knows who can juggle five pots and pans around the stove at once and at the same time be able to make Sherlock sit moodily down to tea and toast for two. John thanks his lucky stars for the Mrs. Hudsons ("Still not your housekeeper!") of the world.
Thanks go to akisura12, who provided the original inspiration for this little fic, and ToffeeRose who brainstormed with me on how best to word things and is generally awesome. ;D