Kokotxas is a traditional Basque fish stew.

The dish is made from stewed fish necks / dewlap (normally from a fatty fish like cod or hake) served with a sauce made from white wine, garlic, flour and olive oil.

[1] In the Basque Country the dish is served with a green sauce (salsa verde / saltsa berde) made from olive oil, flour, garlic and parsley.

[2] The recipe for the green sauce is usually prepared with a few cloves of garlic chopped with parsley and olive oil in an earthenware casserole, all sautéed but without browning, adding salt.

This is removed from the heat and stirred to loosen the gelatin.