Green Bean & Tofu Stir Fry

*from BHG

• 1/2 cup water, divided
• 1/4 cup reduced-sodium soy sauce
• 1 tablespoon tomato paste
• 2 teaspoons Chinkiang vinegar (see Note) or balsamic vinegar
• 2 teaspoons sugar
• 1/4-1/2 teaspoon crushed red pepper, or to taste
• 1 teaspoon plus 2 tablespoons cornstarch, divided
• 1 14-ounce package extra-firm tofu, drained
• 2 tablespoons canola oil, divided
• 4 cups green beans, trimmed and cut in half
• 4 cloves garlic, minced
• 2 teaspoons minced fresh ginger 

1.Whisk 1/4 cup water, soy sauce, tomato paste, vinegar, sugar, crushed red pepper to taste and 1 teaspoon cornstarch in a small bowl. Set aside. Cut tofu into 1/2- to 3/4-inch cubes and pat dry. Toss the tofu in a bowl with the remaining 2 tablespoons cornstarch to coat.
2.Heat 1 tablespoon oil in a wok or large skillet over medium-high heat. Add the tofu and spread out across the surface of the pan. Let cook undisturbed for 2 minutes. Gently turn and stir. Continue cooking, stirring occasionally, until lightly browned and crispy, 2 to 3 minutes more. Transfer to a plate.
3.Reduce heat to medium. Add the remaining 1 tablespoon oil to the pan. Add green beans, garlic and ginger; cook, stirring constantly, for 1 minute. Add the remaining 1/4 cup water, cover and cook until the beans are crisp-tender, 2 to 4 minutes. Stir the reserved soy sauce mixture and pour it over the green beans. Cook, stirring, until thickened, about 1 minute. Add the tofu and cook, stirring, until heated through, about 1 minute more.