2 tablespoons peanut oil, divided
8 ounces skinless, boneless chicken breast, cut into small pieces
1/2 teaspoon black pepper, divided
1/4 teaspoon salt, divided
10 cups sliced shiitake mushroom caps (about 1 pound)
2 tablespoons minced peeled fresh ginger
1 tablespoon minced garlic
3 tablespoons lower-sodium soy sauce
3 tablespoons mirin (sweet rice wine) or 2 tablespoons water plus 1 tablespoon honey
1 teaspoon rice vinegar
8 cups baby spinach (about 6 ounces)
1 3/4 cups chopped green onions
Heat a large skillet over high heat. Add 1 tablespoon oil to pan; swirl to coat. Add chicken; sprinkle with 1/4 teaspoon pepper and 1/8 teaspoon salt. Cook 3 minutes or until chicken is just done, stirring occasionally. Remove chicken from pan.
Add mushrooms, 1/4 teaspoon pepper, and 1/8 teaspoon salt to pan; stir-fry 6 minutes or until mushrooms brown and most of liquid evaporates. Add 1 tablespoon oil, ginger, and garlic; cook 30 seconds, stirring constantly.
Return chicken to pan; add soy sauce, mirin, and vinegar. Cook 2 minutes, scraping pan to loosen browned bits. Remove pan from heat; stir in spinach and onions.
Mark Bittman, Cooking Light