In hot weather, tomatoes are the most appetizing soup. Paired with beef, it is an appetizing tonic soup. 1. Cut tomatoes, beef, potatoes and onions into pieces of similar size. 2. Cook the beef pieces in the pot for a while, remove the color and rinse off the floating foam. 3. Stir-fry onions, add tomatoes, stir-fry red oil, add potatoes and beef, and stir well.