Cook the brown rice according to package instructions. Once cooked, fluff with a fork and let it cool slightly.
In a large bowl, combine the black beans, diced mango, red bell pepper, avocado, cilantro, and green onions.
In a small bowl, whisk together the lime juice, grated ginger, honey or agave syrup, salt, and black pepper until well combined.
Pour the dressing over the black bean and mango mixture, and gently toss to combine.
To serve, place a scoop of brown rice in a bowl and top with the black bean and mango mixture. Drizzle with any remaining dressing if desired.