Add the sliced mango, red bell pepper, red onion, cilantro, and roasted peanuts to a large mixing bowl, arranging them evenly for easy tossing.
In a separate small bowl, combine the soy sauce, vinegar, olive oil, sesame oil, tahini, and sesame seeds, stirring until the dressing is smooth and well blended.
Pour the prepared dressing over the salad ingredients, making sure it is distributed evenly across the mixture.
Toss everything gently using a spoon or tongs until all the ingredients are lightly coated without breaking the mango slices.
Transfer the salad to a serving dish and top with extra peanuts and sesame seeds if desired before serving.