Dry beans and rice are relatively light and travel well. I don't tend to have the patience to cook them, but rice, beans, and vegetables can be found most places and can keep you going provided you have access to ample, clean water. My preferred meals for cooking in camp have become Tasty Bite meals:
Tasty Bite You can filter their available products by whether they are vegetarian or vegan, although I don't think the website is actually showing a complete list of their products. The meals I have picked up are all "heat and eat," and they don't need to be refrigerated. Simply boil some water, put an unopened package into the hot water for 5 minutes or so, then open it and eat. Even if I'm not planning to eat at camp, I like to have a couple of those meals with me in case I don't find a good place to stop throughout the day.