In a large bowl, combine the cooked brown rice, black beans, diced mango, cherry tomatoes, red bell pepper, avocado, cilantro, and red onion. Gently toss to mix all the ingredients evenly.
In a small bowl, whisk together the lime juice, grated ginger, olive oil, salt, and pepper until well combined.
Drizzle the ginger lime dressing over the rice bowl mixture and toss gently to coat all ingredients with the dressing.
Taste and adjust seasoning if necessary, adding more salt, pepper, or lime juice as desired.
Serve immediately or chill in the refrigerator for 30 minutes to allow the flavors to meld together.