13-in (7.5 cm) knob of fresh ginger,peeled and sliced
Cut the rehydrated shiitakes into 1/4-in-thick (0.6 cm) slices (discard the stems if there were any).
In a saucepan, combine the broth, sugar, soy sauce, vinegar, and ginger. Stir in the sliced shiitakes and bring to a simmer. Lower the heat and keep to a slow simmer for 30 minutes. Let the shiitakes cool in the pickling liquid.
Discard the ginger slices. Transfer the shiitakes to a jar and cover with the pickling liquid. The pickled shiitakes are ready to eat immediately. They will keep, refrigerated, for 1 month. Serve with ramen or enjoy as a snack.