Cut the moyu into small cubes (2cm thick), blanch in boiling water for 2-3 minutes. Transfer out and drain. This can reduce the pungent flavor and purify the taste.
Heat a large pot of water to boil and then cook duck chunks for 2-3 minutes, transfer out and drain completely.
Over medium fire, heat cooking oil and then fry the duck chunks for 6-8 minutes until the fat becomes to release and the skin becomes slightly brown. In the process, you need to keep stirring. Add ginger slices in the middle.
Move the duck chunks to the edges and thus form a small hole in the center, add doubanjiang, dried chili peppers and scallion, fry for 1 minute and then mix everything well.
Pour beer along the edges and then cover the lid to simmer for 20-30 minutes (depending on how soft you want the duck to be) and then add moyu chunks to cook for another 10 minutes. Add whole garlic cloves in the middle.
By now, remove the lid and continue cooking for 5-10 minutes until there is only around 1 cup of sauce left.
Add salt to taste if necessary and then add fresh chili peppers. Give a big stir-fry to mix everything well. Serve with coriander decorated.