1 lb Skinned fillets of mackerel
-or sierra Juice of 6 or 7 large limes -(1 1/4 to 1 1/2 cups) 2 md Tomatoes
3 Or 4 canned chiles serranos
-en escabeche 1/4 c Olive oil
1/2 ts Oregano
1/2 ts Salt (or to taste)
Pepper Cut fish into small cubes, about 1/2 inch, and cover them with the lime juice. Set in the bottom of the refrigerator for at least five hours, or until the fish loses its transparent look and becomes opaque. Stir from time to time.