Combine boiling water and mushrooms in a bowl; cover and let stand 15 minutes. Drain and chop mushrooms.
Heat the oil in a large skillet over medium-high heat. Add chopped mushrooms, chopped onion and next 5 ingredients (chopped onions through garlic); sauté 3 minutes. Combine cornstarch and 1 tablespoon water in a small bowl. Add cornstarch mixture, vermicelli, and next 5 ingredients (vermicelli through tofu) to skillet; sauté 2 minutes or until sauce is thick. Spoon 1/3 cup tofu mixture into each lettuce leaf; drizzle 2 teaspoons hoisin sauce over each serving. Sprinkle each serving with 1 teaspoon pine nuts.