Cut chicken into 3/4-inch cubes. Combine chicken and tofu in a bowl with sherry and soy sauce. Add cornstarch, mix well, and refrigerate for at least 10 minutes or up to 4 hours.
Cut whites of green onions into 1/2-inch lengths; slice green tops into thin rings. Set aside.
In a nonstick skillet, heat 1 tablespoon oil over medium-high heat until hot but not smoking. Add marinated chicken mixture and sautee, turning tofu and chicken pieces frequently – until lightly browned. Remove mixture to a plate (chicken will not be fully cooked).
Add the remaining tablespoon of oil to skillet and decrease heat to medium. Add garlic and ginger and cook just until fragrant, 10-20 seconds. Stir in hoisin sauce, cooking for about a minute. Return the chicken and tofu to the skillet and add the whites of green onions. Sautee 2-3 minutes or just until chicken is cooked through. Add the pecans and green onion pieces, tossing to mix.
To serve, heat tortillas. Fill each with one quarter of the chicken mixture and cilantro; roll and serve.
Nutrition information per serving: Calories: 569; Protein: 36g; Carbohydrates: 31g; Saturated fat: 5.5g; Monounsaturated fat: 17g; Cholesterol: 36mg; Fiber: 3g; Sodium: 597mg.