In a small bowl combine the soy sauce, vinegar, sugar, and cornstarch. Par-cook the broccoli in boiling water, then drain and cool it under cold water.
Heat the oil over medium-high heat in a large skillet. Very carefully add the tofu. Cook the tofu, turning once, until light golden brown. Remove the tofu with a slotted spoon and transfer to absorbent paper. Allow the oil to cool a little, then pour most of it into a separate pan, leaving just a little oil in the original pan. Return the pan to the heat and add the onion and bell pepper. Saute until they begin to caramelize. Add the garlic, ginger, and hot peppers. Saute for another minute or two.
Stir in the chicken broth; bring to a boil, than stir in the soy-cornstarch mixture. Bring it to a simmer. Add the broccoli and bean curd to the pan. Cook until the broccoli is heated throughout but not overcooked. Serve with steamed rice.