First and foremost, clean the fish removing all the scales with a small knife. Do not scratch too hard because mullets have a delicate flesh and you could damage the fish.
Once the fish is cleaned inside and outside, give a final rinse under fresh running water.
Cleaned and ready for cooking.
Take a pan, wide enough to contain the fish. Add the olive oil and heat over medium heat.
Once the olive oil is hot, add the chopped garlic.
Immediately after the garlic, add the chopped celery or, if you prefer, you can add them to the pan at the same time.
Sweat off for a couple of minutes or until the garlic start changing its colour.
Then, add half of the chopped parsley you have previously prepared and gently stir for 30-40 seconds.
Add all your chopped tomatoes...
...and stir for few seconds to have an even mix.
Now, season with salt, not too much because later you will taste the sauce and eventually add some more salt if needed.
Finally, season with pepper, turn the heat down to low and cook the sauce for about 15 minutes.
At this point, if the sauce have reduced too much, add a glass of hot water (alternatively, half glass of hot water and few drops of red wine). We need the sauce just slightly liquid because later, when the fish will be placed onto the plate, we will use this sauce to cover.
Now, the sauce is ready for the fish, but before putting the fish into the pan, taste and check for salt.
Then, lay the mullets in the pan.
Both the mullets are now lying in the sauce. If you are cooking small mullets, these should be nearly covered by the sauce. In my case, having to deal with two big fellas, I will baste them with the sauce every now and then.
Cover the pan with a lid...
...and cook for about 15 minutes. If your mullets are small, 10 minutes should be enough to cook them perfectly. Do not turn the fish because this kind of fish is very fragile; a gentle shake of the pan is probably all you need to set the sauce around the fish.
This is me basting the fish after 5 minutes cooking (baste regularly during the cooking). Another 10 minutes and everything should be ready.
When the fish is perfectly cooked, sprinkle with the remaining parsley.
Put the fish onto a plate using a spatula and cover with the sauce. Slices of warm country bread is what you need now and of course a nice glass of chilled white wine.