Six Seasons: A New Way with Vegetables is an absolutely fantastic vegetable cookbook, if the dishes contained within don't change her mind, nothing will.
Six Seasons by Joshua McFadden taught me how to love homemade salads. His flavoring technique is super simple if you look at it (salt, fat, acid, heat basically!) but I needed him to tell me what to do, haha. He has terrific salad dressing recipes that I make all the time and pour over whatever - I especially love the caper-raisin vinaigrette and the bacon vinaigrette.
You could probably cook 90% of the recipes in that book with the same 20 ingredients.
Since it's summertime, here is his recipe for Corn and Tomato Salad with Torn Croutons. I've made this recipe every summer for the last three years. It's great for cookouts and potlucks.
He first became famous for this kale salad recipe. I've made it so many times I don't even need to look at the cookbook anymore. It's a flavor bomb, it's super simple, and doesn't really need anything fancy. The only fancy thing about it is the Parmesan cheese. I've made this salad with the cheap stuff out of the container, but it really is worth investing in a small chunk of the good stuff, especially since you can put it on top of basically any dish and it'll taste good. I think this recipe is a really good one to start with. (He talks about making your own bread crumbs and they really do taste better! It's a fun project to do on the weekend if you have time, and then you can use them throughout the week. But if you don't want to spend the time, just use seasoned bread crumbs from the store.)
I can’t recommend Six Seasons: A New Way With Vegetables enough! Vegetable dishes arranged by what’s in season, makes vegetarian cooking so practical.
Not specifically GF, but Six Seasons from Joshua McFadden is fantastic. Every recipe I've made from this book is delicious. Highly recommend!
I swear I know I plug this cookbook all over this subreddit but it is changing my life on the regular:
Six Seasons by Joshua McFadden is the best vegetable-centric cookbook I own and maybe the best cookbook I own, period? This cookbook helps me figure out:
I think if you listed all of the ingredients listed for ALL of his ingredients for ALL of his recipes in his ENTIRE cookbook, it would probably be less than 50 things. It's all about reusing the same stuff to produce different tasting dishes and I eat all kinds of cool salads now. Here's the one I made for the first time yesterday.
I'm in a cookbook club and this is one of our selections right now, it's WONDERFUL. It's organized seasonally, the recipes aren't insanely complicated and everyone in my club has loved every single recipe they've tried. I'm making my way through it right now because I'm really unfamiliar with winter greens and want to get better. The famous kale salad was so good I ate the whole thing straight out of the bowl last night!!
Here's the kale salad recipe FYI: https://blog.workman.com/2017/09/kale-salad-started/