Combine the broth, soy sauce, oil, juice, lemongrass, and pepper in a shallow pan.
Add the tuna and marinate 30 minutes to 2 hours.
Broil or grill the tuna on each side for about 4 to 5 minutes and serve.
Nutritional Information:
48 Calories (kcal); 5g Total Fat; (86% calories from fat); trace Protein; 1g Carbohydrate; 0mg Cholesterol; 64mg Sodium