In a medium saucepan, bring the rice, 1 tbsp. ginger, 2 1/2 cups water and 1/4 tsp. salt to a boil. Reduce the heat to low; cover and simmer until the rice is tender, about 45 minutes. Fluff with a fork.
Meanwhile, in a small bowl, whisk the soy sauce, vinegar, cayenne and remaining 1 tsp. ginger.
In a large deep skillet or a wok, heat the oil over medium-high. Add the tofu and stir-fry until golden brown, about 5 minutes. Add the bell pepper, bok choy and garlic; stir-fry until the veggies are crisp-tender, about 2 minutes. Add the soy sauce mixture; stir-fry until the tofu and veggies are coated, about 1 minute. Add the rice; stir until combined, about 1 minute. Divide among bowls.