In a medium saucepan, bring the stock to a simmer. Add 6 tablespoons of scallions, the spinach (or arugula), mushrooms, soy sauce and white pepper. Return to a low simmer and cook for 3 minutes. Stirring with a fork, gradually add the eggs in a slow steady stream. Cook until the eggs are set, stirring to create shreds or ribbons of the eggs, 1 minute. Remove saucepan from the heat. Ladle soup into bowls, garnish with remaining scallions. Season with salt to taste and serve immediately. Low Fat, Ready in 15 minutes, recipe by Eggland's Best Nutritional Information1 Serving: Calories 80; Fat 1g (7% calories from fat); Protein 14g; Carbohydrates 3g; Dietary Fiber trace; Cholesterol 58mg; Sodium575mg.