Heat a large skillet on med/hi. Add the olive oil and butter. When the butter is melted, add all ingredients except the wine and the fish.

When the veggies are browned, add the wine to deglaze the pan.

Fill a large stock pot with the 4 quarts of water. Heat on high.

Add the veggie mixture to the water. Bring to a gentle boil and turn the heat down to med/low.

You'll want to keep the boiling to a minimum, so just allow it to bubble a little.

Add the fresh parsley and thyme.

Add the fish heads and bodies.

Simmer for 30-40 minutes and remove the heads only.

Allow the rest of the mixture to continue simmering for about 30 minutes more.

When the heads are cooled enough to handle, remove the flesh and discard any bones. Set aside until completely cooled and refrigerate the meat for use within the next day or so. Otherwise, freeze the meat.

Remove the veggies and fish bodies with a slotted spoon.

Allow the liquid to simmer until reduced by 1/4.

Use a fine wire mesh sieve to strain any remaining solids off.

Ladle the stock into canning jars.

Label the lids to the jars with date and content. Seal and freeze or process with a canning method.