Since I still stand by all of these and am too lazy to re-type, I'm going to start by quoting a more general recommendation I made a couple of years ago in the Vegetarian Cookbooks topic. I'd especially recommend Deborah Madison's The Savory Way and Mollie Kaizen's Still Life with Menu for you, along with Ottolenghi's Plenty and Plenty More.
On 6/19/2020 at 12:00 PM, blue_dolphin said:My top recommendation would go to Joshua McFadden's Six Seasons: A new way with vegetables. It is not strictly vegetarian as he uses anchovies here and there and even includes a recipe for Beef with Lots and Lots of Onions but it's mostly vegetarian and does very good things with vegetables. I've given it to 8 friends and even though it's been a couple of years, I still receive regular text messages with photos of what they are cooking from the book. He starts the book with a "go-to" section of sauces, pickles, compound butters and condiments that he draws on throughout the book. Some people think that's a sneaky way of hiding a recipe-in-a-recipe so be warned. There are photos of most dishes. We have a thread on cooking from it here.
Joe Yonan's Cool Beans is a new title that is full of vegan bean recipes. Beautiful photos, too. I've enjoyed what I've cooked from it so far.
Ottolenghi's Plenty and Plenty More have both been mentioned earlier in this thread and are both excellent. There's a "cooking from" thread on Plenty here . I thought there was one on Plenty More, but I can't find it. Both have tons of recipes with interesting flavor combinations and photos of a lot (though not all) of the dishes. If I were going to give either of those to an Ottolenghi novice who doesn't have access to ethnic groceries, I'd include a pantry gift of sumac, za'atar, pomegranate molasses, harissa, tahini and preserved lemons (or a recipe for that last one.)
I don't see a recommendation for The Moosewood Restaurant Table upthread but it's a great book with a ton of (the cover says 250) recipes, most of which are fairly easy and not particularly time consuming. I'm quite fond of the Hummus with Preserved Lemon....all the dips are good.
I love Deborah Madison, too, and I prefer her Vegetarian Cooking for Everyone to Bittman's How to Cook Everything Vegetarian but while the big tomes are good for reference, they don't draw me in as much as her other books. Vegetable Literacy is a beautiful book that will teach almost anyone a few new things about vegetables. The book is organized into "vegetable families" and there's an informative essay to begin each chapter so it's a good guide to substituting related veg in recipes. Her book, Local Flavors is a great farmers market companion. IMHO, The Greens Restaurant Cookbook, mentioned just above is on the restaurant-y side. For example, most of the soups require their own stocks. The results are generally worth the effort and there are quite a few recipes (Winter Squash Soup with Red Chili and Mint, Turnip Soup with Turnip Greens and Black Bean Chili) that I return to over and over but be aware that it's not entirely effortless cooking. My most used of her books is The Savory Way, which I've used a ton. Both of those are older books and lack photographs which I know is a deal breaker for some but they also happen to be my favorites.
Finally, I'll put in a plug for another old favorite of mine, Mollie Katzen's Still Life with Menu. In this book, she promotes the idea of doing some prep work ahead so dinners are easy to put together at the end of the day. There are 50 menus and each one has a list of prep tasks that can be done 1, 2, or 3 days ahead. There are also quick pasta and stir fry meals, breakfasts and menus for vegetarian Thanksgiving, a vegetarian barbecue and a Seder, all meals that can confound those hosting vegetarian guests. Because of the menu planning aspect, this would be good for someone new to vegetarian cooking or someone who would like a bit of a nudge to get into menu planning or everyday cooking. There are some weekly menu plans at the end with advance tasks to do each day. No photos, the book is illustrated with Katzen's own artwork.
On to newer books, a recent Eater piece, This Cookbook Isn’t Vegetarian. It’s ‘Vegetable-Forward.’ might be of interest to you. Of the books they mention, I'd definitely recommend Hetty Liu McKinnon's Tenderheart for you. It's organized by vegetable and they're all widely available, nothing that only turns up a special farm markets on the first full moon after the last frost. The recipes are all straightforward and I've enjoyed everything I've cooked from it. There's a photo for every dish, everything is vegetarian with suggestions to vegan-ize all but the egg-centric dishes.
I also really like Abra Berens' three books, Grist (with a focus on grains and legumes), Ruffage (focus on vegetables) and Pulp (focus on fruit). I think of them as "idea" books because they are full of variations, riffs and suggestions for substitutions. They have a limited number of photos and some of the recipes are barely sketched out (a few in Ruffage are literally just little drawings!) so I wouldn't recommend them to someone who doesn't know how to cook but someone who knows what they like and enjoys taking ownership of what they're cooking can find some great ideas to run with. You might appreciate the sections in Grist on "a week of _______ with no boredom" where the blank might be black beans, barley, etc. There are photos, but relatively few of them.
Also mentioned in that article, I just got Susan Spungen's VEG Forward but haven't cooked from it yet and I have Nik Sharma's VEG TABLE on pre-order and am looking forward to it.
If you like Ottolenghi's style but aren't sure about Plenty and Plenty More, the recent Ottolenghi Test Kitchen book Extra Good Things by Noor Murad might be one to consider because of its tables and pull-outs to help choose recipes (see my post here to see what they look like.)