One of the things that I have still been struggling with in over a year of being in grad school is how to eat healthily and on a budget while minimizing the amount of time I spend on cooking. For people who have been in grad school longer and/or have optimized this aspect of their grad life, mind sharing what you do?
I don’t have a cuisine preference, as long as it is (ovo-lacto) vegetarian. But you don’t have to restrict yourself to my preferences as your tips may help others as well. 
If you don’t own a slow cooker, get one asap. You can get something decent for like 30-40 bucks. Buy beans, lentils, oats in bulk.
I like to do a bean chili every 3ish weeks. I don’t go by a recipe, but you might want to. I usually just do something like: toss together black/pinto/kidney beans + a can of crushed tomatos (you can be fancy and chop up some real tomatoes if you want), onions, carrots and keep it in the slow cooker for a few hours.
For the meat eaters out there: I like buying chicken legs when they’re on sale at Whole Foods/HPP. They’re great b/c you can enjoy them for the meat, and then also save the bones for broths in the future. I toss my bones in a bag in the freezer after eating the meat off them. Then when I cook beans in the slow cooker, I’ll generally add some chicken bones to the mix to give it a richer flavor.