Start with high-confidence vegetarian cooking books, then narrow by subgenre or adjacent topics.
Chez Panisse Vegetables
Alice L. Waters
Plant Over Processed
Andrea Hannemann
The Happy Healthy Plant-based Cookbook
Dusty Stanczyk, Erin Stanczyk
Mostly Veggies
Brittany Mullins
Half Baked Harvest Every Day
Tieghan Gerard
The Bean Cookbook
Tami Hardeman
PNW Veg
Kim O'Donnel