Suggestion ... Daughter wants vegan quiche. ... Daughter provides vegan recipe.
Instead of making quiche requiring slicing, perhaps make tarts/tartlettes for individual servings.
Pre-portioning would be dealt with and you won't have to worry, will it crumble as you slice? or flop apart when you serve? The smaller size would let those who want to try more than one flavour to do so. For the vegan option, a slice of potato would fit nicely into the bottom of a tin.
Yes, you may not have one of these pans, but it could be a good investment and well used for multi-purposes. After getting rid of so many pans with your move, time to treat yourself to the one of your desires!!
Bon Appetit!
On another note ....
Now you have us all wondering what quilty things you will be gifting at the shower!