Preparation:

1. Preparation of the stuffing:

   - Rehydrate the shiitake mushrooms for 30min in hot water, until they are soft. Rinse them then remove the stems from the mushrooms. Finely mince the mushrooms.

   - Very finely mince the chicken and the onion

   - Peel the ginger with a spoon and mince it finely.

   - Finely slice the onion.

   - Combine the chicken, scallion, ginger, onion and mushrooms in a bowl. Add the soy sauce and sesame oil and mix again.

2. Preparation of the ravioli:

   - Place a spoonful of stuffing in the center of a ravioli sheet. 

   - Using your fingers and a little water, wet around the ravioli leaf. Fold the ravioli sheet in 2, pinching in the center to close the ravioli sheet at one point.

   - Then make 2 folds on each side of the ravioli, folding each fold towards the sealed center.

   - Finally, pinch the 2 open ends to completely close the ravioli, being careful not to pierce the ravioli sheet.

   - Repeat until no more stuffing.

3. Cuisson:

   - In a saucepan, add a tablespoon of vegetable oil and heat over high heat.

   - Once the oil is hot, add the ravioli and sear them.

   - Once the underside of the ravioli is golden, add 1cm of water to the pan (without sprinkling the top of the ravioli). Cover and cook until the water has completely evaporated.

   - Once the water has evaporated, take the ravioli out onto a plate. 

   - Dress and serve with the gyoza ravioli sauce, which can be garnished with spring onions, ginger and sesame seeds.