In a large pot, heat a few tablespoons of water over medium heat. Add the red onion, then cover and cook until softened, stirring occasionally, about 7 minutes. Stir in the garlic and cook another 2 minutes. Add a little more water, if needed, to prevent the onion and garlic from sticking to the bottom of the pot.
Add the sweet potato, bell pepper, jalapeño (if using), and Vegetable Broth 2.0. Bring to a boil. Lower the heat to medium-low, cover, and simmer until the sweet potatoes are tender but still firm, about 25 minutes.
Blend together the white miso paste and hot water.
Stir in the beans, tomatoes in their juice, and miso mixture, then simmer gently, uncovered, until heated through, about 5 minutes. Add the mango and cook for 1 more minute, then stir in the cilantro and serve hot.