DS became a pescatarian a number of years ago, then became a vegetarian, now is bordering on vegan (will eat some cheese and milk products). My first piece of advice is to avoid the processed, fake foods (as others have also suggested). I also avoid soy. One of the best resources I’ve found for information and recipes is mynewroots.org. The recipes are vegetarian, most are vegan, many are gluten-free. I’ve learned a tremendous amount from this blog, and I’ve made many of the recipes. They’ve all been successful, delicious even for teenaged boys. Some of the recipes have a lot of ingredients, but you can leave many out. For example, one of our favorites is:
http://www.mynewroots.org/site/2013/07/flavour-bomb-greens-n-noodles/
I skip most of the toppings (one son is allergic to nuts, I don’t like sesame seeds, I don’t always have cilantro or mint). Basically it’s a pile of shredded greens over brown rice noodles with a nice dressing (you can leave out some of those ingredients, too). She has some nice seasonal “bowls” - again, I usually leave out several ingredients. Her lentil soup and lentil salads are great. I’ve tried quite a few soups, all wonderful. These are the best brownies I’ve ever had:
http://www.mynewroots.org/site/2015/02/chocolate-chunk-nut-butter-blondies/
They do have eggs but they are grain-free. There is a cookbook, but the recipes tend to be on the complex side.
Another good site is ohsheglows. Most of her recipes are too complicated for me, but there are some we like. The cauli-power fettucini alfredo is incredible - the sauce is mostly cauliflower. I use some real Parmesan instead of the cheese substitute.
I’ve also come up with some quick dinners. For example, brown rice pasta (Trader Joe’s has great brown rice spaghetti and Whole Foods has some good brown rice pasta, too) tossed with cannelini beans (from a box, drain in colander, then drain pasta on top; the hot water warms the beans) and greens (baby spinach, kale, chard), with bottled peanut sauce.
Smoothies are good for protein. I learned about hemp hearts on mynewroots - it’s a vegan source of complete protein.