Bring a medium pot of water to a boil, add green beans, and cook until bright green, about 3 minutes. Drain and rinse with cold water. In a small bowl, mix lime juice, soy sauce, and pepper, then set aside.
Cut tofu into 1/2-in.-thick rectangles. Heat oil in a nonstick frying pan over medium-high heat. Add tofu, sprinkle with sugar, and cook, turning occasionally, until evenly browned, about 10 minutes. Stir in shallots and cook until browned, about 3 minutes. Add green beans and cook until warmed, about 3 minutes. Pour in soy mixture and stir to coat.
Note: Nutritional analysis is per serving.