In a large bowl, add the drained and rinsed kidney beans. Use a potato masher or fork to mash them until no whole beans remain.
To grate the raw beets, peel them and chop off the ends, then chop into smaller pieces. Place in a food processor and process until the pieces are shredded and small. You could just use a hand grater, but this is a lot of work!
To the mashed beans, add the grated beets, diced red onion, minced garlic, thyme, smoked paprika, salt, ground flaxseeds, tahini and quick oats. Stir with a large spoon until well combined.
Form into burger shapes, about 3-4 inches wide and about 1/2 inch thick.
In a large non-stick or cast iron pan, heat a few tablespoons of vegetable oil over medium heat. Carefully place the burger patties on the pan and fry for about 4 minutes, then flip and cook for another 4 minutes, until golden.
Remove from the pan and serve immediately in buns with toppings of choice.
For the Sriracha Mayo: Whisk all ingredients in a small bowl until well combined.