In a medium bowl, toss the pork, 2 tbsp. hoisin sauce and the orange juice.
In a large nonstick skillet, heat 2 tsp. oil over medium-high. Add the pork mixture and cook, stirring occasionally, until lightly browned and cooked through, about 4 minutes. Transfer the pork to a plate.
Add the remaining 1 tsp. oil to the skillet. Add the mushrooms; cook, stirring often, until lightly browned and softened, about 6 minutes. Stir in the cabbage and carrots; cook, stirring often, until crisp-tender, about 3 minutes. Add the pork, remaining 6 tbsp. hoisin sauce and the scallions; cook, stirring constantly, until heated through, about 1 minute.
Place warmed tortillas on plates and top with the pork mixture. Fold over.
