Slice the onion to a thickness of 1/4 inch. In a medium skillet, sauté the onion in the oil over medium-high heat for 10 to 15 minutes, until it starts to darken and caramelize. Turn down the heat slightly and add the grated beets along with the garlic, walnuts, raisins, and paprika. Cook for 10 minutes, stirring often.
Transfer the contents of the skillet to a food processor and pulse several times until chunky. Transfer the onion mixture to a large bowl and mix in the lentils, 2 teaspoons salt, and 1 teaspoon pepper.
Pulse the rice and egg in the food processor to form a coarse puree, then add the rice mixture to the bowl with the onion-lentil mixture. Mix well with your hands.
Lightly oil your hands and divide the dough into 8 portions. Shape each portion into a patty just under 1 inch thick.
Heat a heavy-bottomed skillet over medium-high heat and add oil to coat the bottom. Place the burgers in the skillet and cook undisturbed for 5 minutes. Gently flip the burgers and turn down the heat to low. Cover and cook for 10 minutes, until the burgers have a firm, brown crust.
Serve the scarlet burgers on grains, greens, in a pita or on a bun. Top with Butterworks Farm Nonfat Plain Yogurt and fresh dill.