Pat the chicken dry with paper towels and season salt and pepper. In a large bowl, combine 2 tablespoons of soy sauce, 2 tablespoons rice wine vinegar, and the grated ginger and garlic. Add cubed chicken and set aside to marinate for 15 to 20 minutes.
Using a large slotted spoon or strainer, transfer the marinated chicken to new large bowl, discarding the excess marinade.
Sprinkle in 1/4 cup cornstarch and toss to coat.
In a large pot, heat 1/2 inch of oil over medium-high. Working in batches, add the coated chicken in a single layer and fry, turning occasionally, until golden brown and cooked through, about 4 to 5 minutes per batch. Move to a large paper towel-lined plate or wire rack set in a baking sheet to cool. Cubes will be crunchy looking nuggets of magic, and just get crunchier as they cool. Resist urge to eat them all from the baking sheet.
In a small bowl, whisk together the remaining 1 tablespoon cornstarch and 2 tablespoons water to form a slurry. In a large saucepan, combine the remaining 1 tablespoon of soy sauce, honey, orange juice, marmalade, ketchup, remaining 1 tablespoon of rice vinegar, and sesame oil. Heat over medium until just starting to bubble at the edges, then add the slurry, a spoonful at a time, while whisking, to thicken the sauce. Turn off the heat. Add the chicken cubes to the pan and toss to coat.
Serve the chicken and remaining sauce from the pan with rice and broccoli like the homemade takeout champ you ARE.