The Laws of Transfiguration

Molly Weasley sighed. This was the chore she hated the most. Food shopping. Not because it was difficult, as such, but because it was such a bore. Glancing around Grimauld Place's kitchen, she found the food fund jar, once again on a different worktop. The Order members couldn't resist moving it, it seemed.

Initially, Molly had been reluctant to accept the funds, but after two days of catering for twice or even thrice the usual number of people, she'd found her pockets just a little too empty. Arthur had asked around, and found most Order members were more than willing to drop a few sickles per meal into a jar to offset the cost of the most fabulous cooking available.

She dropped the pile of silver into her purse, and flooed to Diagon Alley.

"Mrs Weasley, how do you conjure food?"

Molly looked up at the earnest brunette watching her cook. "I'm sorry, my dear, what was that?"

"How do you conjure food?" Hermione repeated. "I read that food cannot be conjured, it breaks one of the rules, so-"

"Hermione," Molly said, cutting across the flow. "I take it that was an OWL level text?"

Hermione nodded. "I think it was Gamp's Law of Elemental Transfiguration," she clarified.

"That one," Molly smiled. She stopped making lunch sandwiches and sat down at the table, motioning Hermione to join her. "You see, Gamp's Law isn't so much a law, as a joke," she explained. "It says that conjuring is the most useful way to obtain desperately needed supplies at extremely short notice. The five principle exceptions are food, clothing, gold, magic items, and any living thing, including living plants and animals. There are different reasons for all of these."

She picked up her wand, and cast five spells, creating one example of each. She picked up the first, a small cupcake. "This looks right, and it would probably taste right as well. But your tummy wouldn't digest it properly, and if you lived mainly on conjured food for long enough, you'd either starve or suffer massive system failure."

"It wouldn't be a permanent conjuration then?" Hermione asked. "You wouldn't be able to digest properly, I would guess."

"I suppose," Molly agreed. She picked up a single sock. "Put your hand in this."

Hermione did so, and Molly could see the shock on her face as the wool unravelled around her fingers. "Either the weave or knit fails, or it comes out as a sheet of material. Arthur brought home some muggle stuff that resembled it. Cling film, I think he called it." Hermione nodded; clearly the muggleborn was familiar with it. Molly pointed to the small gold bar. "This is basically slightly more enduring Leprechaun gold, and the Goblins would never accept it anyway. Now try this broom."

Hermione took the broomstick. "In here?" she asked dubiously.

"It'll be alright; trust me," Molly assured her. The girl mounted the broom, kicked off, and hardly left the ground. Flushing slightly, she put the broom down again.

"I see the problem with that, and I guess your mouse there isn't properly alive," she speculated. "But then how do you make the food?"

"That is a secret between housewives and house elves," Molly smirked. "Look at this."

She opened the cupboard and handed Hermione a large jar. "'All-purpose basic foodstuff'," Hermione read. "'All the nutrients in the right proportions. Transfigure to your heart's content, it reverts to the raw form upon consumption.' It looks incredible!"

"It is," Molly agreed. "I'm not sure how they make it, but it's much cheaper than actual food, and easier to transfigure. I like to turn it into ingredients and then cook it myself, but if I'm in a hurry I can just do an Aguamenti water charm and make instant hot soup."

"Is this in all wizarding food?" Hermione asked.

"Yes and no," Molly shrugged. "Most house elves use it, and it's normal to use it to make normal meals, but Honeydukes, Fortescue, Bertie Bott, they all use real ingredients. It's why Hogwarts can get away with serving such heavy, greasy food. It all turns back into a nice balanced mix in your tummy. Actually, Fortescue and most wizarding restaurants have the option of having your food made from this as a diet alternative. Doesn't taste quite the same, but it does the trick."

Hermione nodded slowly. "Makes sense." She grinned. "I've got to make a note of this to tell Harry. Thanks, Mrs Weasley!"

Molly watched contentedly as the girl ran off, then frowned at the jar. Maybe she should make a little extra for dessert this afternoon. After all, it was healthy.

AN: If this ever happened, the horcrux hunt would have been pretty different.

It's an attempt at reconciling the description of Molly cooking in Chamber of Secrets with what Hermione says about Gamp's Law. Hope it makes sense.