The simplest thing is chicken soup. Go to the supermarket to buy an old hen with white stripes, put the whole chicken in a casserole, fill it with water (just before eating the chicken), boil water on high fire, skim off the foam floating on the water, then add onion, ginger slices and star anise, turn down the fire, stew for 2-3 hours, and add salt to drink delicious chicken soup. Remember to buy an old hen, because people are more likely to catch a cold in winter. Chicken soup contains special substances, which can enhance human immunity, help drive away influenza virus and slow down cold symptoms.