When the lentils are almost finished cooking, heat a large skillet over medium heat. Once hot, add oil and onion and season with a pinch each salt and pepper (amount as original recipe is written // adjust if altering batch size). Stir to combine, and sauté for 4-5 minutes, stirring frequently, or until the onions are tender and slightly browned.
*Most hamburger buns are naturally vegan. Just check the package to make sure there aren’t any animal products. The only brand of Vegan/GF buns I’ve liked are by the brand Happy Camper. I also like Udi’s, but they do contain eggs.
*Nutrition information is a rough estimate.