How to Make It
Heat a large skillet until hot. Add the oil, followed by the beef and pork. Season with salt and cook over high heat, stirring and breaking up the meat, until crumbly and lightly browned, about 3 minutes.
Stir in the chile-bean sauce, hoisin and soy sauce and cook, stirring, for 3 minutes. Gently fold in the tofu. In a small bowl, whisk the cornstarch into the water. Add to the skillet and simmer until the sauce thickens, 2 minutes. Stir in the scallions and serve.