- Cut the onion into julienne and sauté a little.
- In a pot put the oil, onion, fillets, bay leaf, salt, vinegar and water or broth over high heat and cover until it begins to boil.
- Then you have to lower the heat and leave to boil until the onion is tender.
- Do not forget to remove and look from time to time so that you do not lack water. It must be in its juice.
Note: the touch of vinegar is important, you should know but do not pass.