For 2 people
1 skate wing
1 big onion
Bouquet of thym
2 laurel leaves
Salt and pepper
2 egg yolk
1 tablespoon flour
100 g butter
Peel and cut the onion. Boil water in a pot. Add the onion, thym, laurel, salt, pepper and the wing. The wing needs to be submerged. Simmer for 20 minutes.
Prepare 2 saucepans, one fitting into the other. In the small saucepan, mix the butter, the egg yolk, the flour and the mustard.
In the bigger saucepan pour 5cm of water and boil. Stop the heat and put the small saucepan inside the bigger one. Mix until getting a thick sauce. Poor a tablespoon of the skate stock in the saucepan, mix. Repeat until getting the consistency you want.
Remove the skate wing from the stock. Remove the fishbone and cartilage.
Serve the skate with the sauce.