Preheat oven to 400ºF.
Add ground chia seeds to ¼ cup of water and stir with a wire whisk. Set aside to thicken.
Add pinto beans to a large mixing bowl and mash with a potato masher. (I find twisting the masher as I press down works well.)
Add chia seed mixture, lentil taco meat, mashed sweet potato, pumpkin sees, salsa, onion, celery, garlic, nutritional yeast and taco seasoning to the mashed pinto beans and stir with a large spoon until well mixed.
Add cooked quinoa to the mixture and stir until well mixed.
Line a large baking sheet with parchment paper.
Form burger mixture into patties by rolling and flattening large spoonfuls between your hands.
Place patties on parchment paper and lightly brush tops with olive oil.
Bake at 400ºF for approximately 15 minutes then carefully turn patties, brush tops with olive oil and bake for another 15 minutes.