Genshin Impact is filled with small quests that are hidden throughout the world. Some of them offer some sweet rewards. You can find the Old Tastes Die Hard quest near the Luhua Pool, on the southeast near the cliff. There is a small building there with a man sitting outside.
If you speak with the man, he will tell you that he has been trying to find an old dish that he used to eat. He thinks the name of it was the Sweet Mistress, and he asks you if you might find the recipe for him.
What he doesn’t realize is that the meal is actually called the Sweet Madame, so if you make that for him, he will be happy. You will need two Foul Meat, and two Sweet Flower to make it. You can get Foul Meat by killing any of the birds that you see flying around the game. Sweet Flower will grow in clusters in grass anywhere on the map and can be found quite close to the man’s location if you don’t have any.
There is also a cooking pot right beside him, but you will need to light it with a Pyro ability to be able to use it. Cook up the food and give it to him, and he will be happy and give you the recipe for Zhongyuan Chop Suey. This is a 3 star dish that you will need three pieces of meat, three pieces of fish, three bags of flour, and two serving of salt to make. It will reduce the stamina consumption of sprinting by 15-25% for 900 seconds.