"Grandma style" refers to a way of doing something, like cooking, where you follow traditional and old-fashioned methods that were commonly used by grandmothers.
Sentences with «grandma style»
The delight of «toddler grandma style» — love this point of view on fashion! (thebostondaybook.com)
They were more grandma style than the style of someone in their 20s. (xobeverly.com)
Next dress up event, I'm wearing grandma style loafers. (theinspiredroom.net)