In medium-sized pot bring 2 cups of water, ¾ cup lentils, and ⅛ tsp salt to a boil. Cover with a tilted lid and reduce heat to a simmer, cooking for 20-25 minutes (depending on type of lentils) until tender. Strain any excess water.
Meanwhile, heat a large skillet on medium heat with 2 tsp avocado oil. Once hot, add onions and cook until softened, about 5-7 minutes. Stir in garlic and 1 cup green peas and cook 1-2 more minutes, until fragrant. Turn off heat and set aside to cool a bit.
In a large bowl, place 3 Tbsp flaxseed, ¼ cup almond or peanut butter, 3 Tbsp tamari, fresh cilantro, 1 Tbsp cumin, and 1 Tbsp chili powder. Add cooked lentils and onion/pea mixture once those finish cooking. Add ¾ cup bread crumbs and mix everything together.
Form patties with your hands, adding more breadcrumbs if needed. Patties should be easy to form and slightly tacky but not too sticky. Place patties on a parchment-lined baking sheet. If you have the time, refrigerate for 1 hour, but it's not required.
Once ready to cook, preheat oven to 400°F.
Brush patties lightly with olive oil before cooking. Bake for 20-25 minutes, until both sides are lightly browned, carefully flipping after 15 minutes. Once veggie burgers finish cooking, allow to rest for at least 5 minutes before handling in order to firm up.
Assemble veggie burgers on a lightly toasted buns with all your favorite burger toppings and condiments. Enjoy!