When the oil is hot place the shredded tofu, cook them until it turns golden brown. Set asides. Add a little bit oil in the skillet then sauted the mushroom until just brown. Then add the tofu back into skillet and mix it up. Add the hoisin sauce, soy sauce, sriracha, and sugar. Combine together add the lemon juice and mix them well. Taste it before turn of the heat. Set asides.