Weight Watchers tomato and red onion soup is a real favourite. This easy-to-cook tomato soup with a dash of Tabasco sauce makes a delicious lunch or light dinner for anyone who's watching their weight. This recipe serves 3 people and will take around 40 mins to make. We'd recommend making this delicious soup in a big batch so you can freeze some for future lunch or dinners when you're short on time. This lower-fat soup recipe is perfect if you're trying to be healthy and you're counting calories. The tangy red onion, sharp tomato, Tabasco sauce and hint of garlic make one mouth-watering combo.