Brown fish over high heat on one side, about 1 minute.
It is not enough to pass them through or over heat.
Place over high heat, cover and cook for 2 minutes.
Add water to cover, and bring to a boil over high heat.
Place the stock in a large pot over low heat.
Cook over relatively high heat about 2 minutes on one side.
Cook over very low heat until soft but not brown, about 30 minutes.
Place a large skillet over high heat and add the oil.
Brown well over high heat on all sides, turning as necessary.
Place over high heat and bring just to a boil.