In medium bowl, combine soy sauce, cornstarch, 1 teaspoon oil, and pork strips. Marinate 5 minutes. Meanwhile, in small nonstick skillet, heat butter over medium-high heat. Add eggs; scramble until cooked but not dry. Transfer to large bowl and set aside.
In large nonstick skillet, heat 2 teaspoons oil over high heat. Add pork and cook, stirring, until browned, about 2 minutes. Transfer to bowl with scrambled eggs.
Heat remaining oil in skillet, and add pepper, mushrooms, onions, garlic, and ginger. Stir-fry until vegetables are softened, about 3 minutes. Add bean sprouts; cook 1 minute more. Add broth; heat to boiling; stir in eggs and pork.
Warm tortillas in microwave, about 30 seconds, and brush hoisin sauce over centers. Divide vegetable-pork mixture among tortillas and roll up.