To prepare lentils, bring vegetable broth to boil. Add lentils and simmer for 35-40 minutes, until all water is absorbed.
In a small pan, heat olive oil at medium. Add onion and garlic and sauté for 5 minutes. Add mushrooms and saute until everything softens (7-10 minutes).
Preheat oven to 375°. Grease a baking sheet.
When lentils are cooked, transfer them to a large mixing bowl. Use a potato masher to mash them, leaving a little texture.
Stir in mushroom mixture and all remaining ingredients. Mix until thoroughly combined.
Wet hands and form patties, using about ¾ cup mixture for each. There should be enough to make 6 large or 8 medium burgers. Place on baking sheet.
Bake for 25 minutes then remove from oven and flip burgers. Return to oven and bake for another 10-15 minutes, until the outsides are crispy. Serve right away, refrigerate or freeze for later.
Recipe by The Colorful Kitchen at https://thecolorfulkitchen.com/2016/03/21/7003/