Set up a steamer. Preheat the oven to 350°F. Line a baking sheet with parchment paper, lightly grease it with the canola oil, and set aside.
Place the potato in the steamer and steam for 10 minutes, until tender when pierced with a paring knife. Remove from the heat and set aside to cool.
Place a pot of water over medium-high heat and bring to a boil. Add the beets and boil for 10 minutes, until tender when pierced with a paring knife. Remove from the heat and set aside to cool.
Peel off and discard the beet skin. Put the shredding blade in the food processor and put the lid on, drop the potato and beets through the feed tube to shred them. Scrape the shreds into a large bowl.
Place the walnuts in the bowl of a food processor fitted with the “S” blade and pulse until they are minced to the size of cooked ground beef crumbles. Scrape them into the bowl containing the potato and beet mixture.
In a cup, whisk together the vital wheat gluten, nutritional yeast, agar, and smoked salt. Sprinkle the mixture over the bowl containing the potato mixture.
In a second cup, stir together the coconut oil, tamari, and Kitchen Bouquet and pour it over the potato mixture. Using your hands, toss the mixture together, trying not to mash the potatoes too much.
Using a ½-cup measure, form the dough into five patties. Place the patties on the pan and flatten them to a ¾-inch thickness. Spritz or brush them with more of the canola oil. Bake for 30 minutes, turning the burgers once halfway through the cooking time, or until they look toasted and are firm to the touch. Remove from the oven.