Heat olive oil in a large skillet over medium heat. Add the chopped cauliflower, onion, celery stalk, and carrot. Cook until just tender (5-7 minutes). Add the shredded sweet potato and garlic to the pan. Mix veggies thoroughly and then add the cumin, oregano, salt, and pepper. Mix well and allow the veggies to cook for another 5 minutes until tender. Remove pan from heat and allow the veggie mixture to cool.

While the veggies are cooling, in a food processor grind the sunflower and sesame seeds, making sure not to over-process. Pour the seed mixture into a separate bowl and mix in the ground flaxseed. Set aside. Next, place the veggie mixture into the food processor and pulse veggies until all of the larger chunks are gone. Add in the seed/flax mixture and pulse a few more times. Finally, add the flax egg and pulse until mixture is well combined. Be careful not to over-process the mixture.

Preheat oven to 400 degrees. Line two cookie sheets with parchment paper. Scoop about ⅓ cup of the mixture into your wet hands and form a ball. Place the ball onto the parchment paper and form into ½ inch thick round patties. (If too moist, stick in freezer for 5 minutes.)

Place the trays into the oven. Remove after 15 minutes and flip carefully with a spatula. Place back into the oven for another 10-15 minutes. Once the burgers are golden brown, remove the pan from the oven and place the burgers on a cooling rack. Let cool for 5 minutes before serving. Store in an airtight container in the refrigerator up to 4-5 days or in the freezer for 1 month.

*Reheat in a toaster oven.