Peel and dice the onion. Heat oil in a large pan over medium heat, then add the diced onion and sauté for about 10 minutes, stirring frequently to prevent sticking or burning. While the onion cooks, peel the garlic and ginger, then finely chop them. Prepare the beet by peeling it with a vegetable peeler and cutting it into rough cubes. Once the onion is soft and golden, stir in the chopped garlic, ginger, and beet. Mix well to combine. Add the ground coriander, cumin, turmeric, chili powder, and smoked paprika. Stir thoroughly, cover the pan, and let the mixture cook for 7 to 10 minutes, until the beet cubes are tender—smaller cubes will cook faster. Drain and rinse the canned pinto beans, then add them to the pan. Stir everything together and cook for another 2 to 3 minutes to let the flavors meld. Season to taste with salt and pepper. Finish with a sprinkle of chopped cilantro for garnish. To serve, spoon the warm filling into taco shells and top with guacamole, Greek yogurt, or your favorite toppings. Enjoy!