Cong shao hai shen (葱烧海参, scallion-braised sea cucumber) is considered one of the most challenging and prestigious preparations in the Shandong culinary canon — a test of both ingredient preparation skill and sauce-building technique. Sea cucumber (海参, hai shen) must undergo an elaborate rehydration process before cooking; the finished dish should have a sea cucumber that is silky, deeply savoury, and saturated with a glossy scallion-braised sauce, resting in a pool of intensely flavoured braising liquid that has been reduced to a near-glaze.
Sea cucumber rehydration (the critical preparation, 3-4 days): Day 1: Soak the dried sea cucumber in cold water for 24 hours until soft. Day 2: Place in cold water in a covered pot. Bring to a boil, turn off heat, leave to cool slowly. Repeat once more. Day 3: The sea cucumber should now be pliable and significantly expanded. Cut open and remove internal organs and calcified ring. Rinse thoroughly. Repeat the boil-and-cool process. Day 4: The sea cucumber is fully rehydrated and ready to cook. It should be 4-5 times the size of the dried original. The scallion braise: Fry 100g large scallion (da cong, cut into 5cm pieces) in generous neutral oil over medium-low heat for 10-15 minutes until deeply caramelized and fragrant — this is the essence of the cong shao technique. The scallion oil is now the cooking medium. Add 200ml superior stock (qing tang), 2 tbsp Shaoxing wine, 2 tbsp light soy, 1 tbsp oyster sauce, 1 tsp dark soy, 1 tsp sugar. Add the rehydrated sea cucumber. Braise 30-45 minutes over low heat. Reduce the sauce to a glaze. Finish with a cornstarch slurry to coat.
Insufficient rehydration: Under-rehydrated sea cucumber is rubbery and will not absorb the braising sauce. The 3-4 day process cannot be shortened. Using inferior stock: The braising sauce depends entirely on the quality of the stock — use the best possible qing tang.
Fuchsia Dunlop, Invitation to a Banquet (2023)