For sauce, stir together soy sauce, lemon juice, sugar, and oil; set aside.
Place steamer basket in a very large skillet. Add water to just below the bottom of the steamer basket. Bring to boiling. Add broccoli; cover, reduce heat,and steam for 4 minutes. Add the red and/or yellow sweet peppers; steam for 3 to 4 minutes more or until vegetables are crisp-tender. Drain and transfer vegetables to a serving bowl. Drizzle sauce over vegetables, tossing gently to coat. Makes 12 servings.