I originally posted this bit of advice ages ago on Tumblr, but it always bears repeating for new and experienced GM's alike.
Just because it's not in the rulebook doesn't mean you can't make it happen.
Being a GM often means knowing when to bend the rules of the game to accommodate interesting and good ideas your players have, or adjusting/reskinning class features for your players so they best suit their characters.
In my games, Arella's character Prianna is a bard whose magic comes from the performance of cooking. She weaves healing and buff spells into her baking and cooking, and uses spices and herbs as spell components. That's already not a hard thing to change.
A bard's bardic focus item is traditionally any kind of musical instrument. For bards who perform via singing, that focus could be choker or pendant, or maybe a tuning fork. For bards that perform via dance, it could be a ribbon that ties their hair back, or a particular outfit, or maybe a magical pair of shoes. In Prianna's case, since she's a chef, her focus is a frying pan. It's the tool she uses to perform with.
And as anyone who's cooked with a cast iron skillet can relate, those things could easily do 1d6 bludgeoning damage.
The important take away is this: tabletop roleplaying games are a series of mathematical systems and dice with story and flavour draped over them. If the math and die rolls remain the same, I say the story and flavour that's over them can be changed to whatever a player likes.
Ultimately, what's more important: The verisimilitude of a make believe world, or the enjoyment of your players? I'm almost always going to go with the latter.