Put the quinoa in a bowl, cover with water, then drain. Repeat twice and drain well. (This will help remove any bitterness.) Transfer the quinoa to a medium saucepan and cook over medium heat, stirring constantly, until the quinoa is dry, about 8 minutes. Add 1 1/2 cups of the vegetable broth, 3/4 cup water and 1/2 teaspoon salt and stir together. Bring to a simmer, then cover the pan, leaving the lid slightly ajar to let steam escape; reduce the heat to medium low and cook until the quinoa is tender and the liquid is absorbed, about 15 minutes.
Meanwhile, heat the oil in a large skillet over medium heat. Add the garlic and red onion and cook, stirring often, until slightly softened, about 4 minutes. Add the chile powder, coriander and cumin and cook, stirring, until the spices darken, about 1 minute. Add the remaining 1 1/2 cups vegetable broth, the Brussels sprouts, jalapeno, sweet potatoes and 1/2 teaspoon salt. Increase the heat to medium high and bring to a simmer. Cook, stirring occasionally, until the Brussels sprouts and sweet potatoes are tender and the liquid is almost absorbed, about 15 minutes.
Meanwhile, bring a small saucepan of water to a boil and prepare a bowl of ice water. Gently add the eggs to the pot with a spoon. Simmer for 6 minutes, then transfer the eggs to the ice water. Let sit until cool enough to handle, about 3 minutes. Peel and halve the eggs and set aside.
Add the Brussels sprout mixture, cilantro and lime juice to the quinoa and toss; season with salt. Divide among 4 bowls and top each with some cashews and half an egg.