Culinary purpose of frying pan foil sheet for cooking fish? (not wrapped in foil)

Question

I came across some videos about how to cook mackerel (Chef Saito's Saikyo-zuke with Spanish Mackerel [Japanese Cooking] - Dining with the Chef) and several of them recommended the use of a "fish cooking sheet" that looks to me just like aluminum foil. They put this foil on top of a frying pan and then put the fish on top of the foil and then cover with a glass lid on low heat for 3-4 minutes before flipping.

Note, the fish is not sealed inside the foil with herbs and spices, and the recommendation is for low heat.

If any, what is the culinary purpose of using foil for frying pan (when cooking oily fish)?

It says one side is non-stick, but surely it is not just for help with clean up? Does it modify the heat in some special way not otherwise achievable without the use of foil?

The foil is from Japan, but the pictures on the packaging make it clear what it's used for.

[Bulk Purchase] Kitinto-san Foil Sheet for Frying Pans, Wide 11.8 x 2.6 ft (30 x 7 m) x 4 Packs

Answer 1

It's a silicone-coated aluminum foil.

It's just something that makes your life easier when cleaning. You could just use a regular non-stick pan to get the same benefits.

There's no "culinary purpose" for it.

Answer 2

In my experience, when using non-enameled cast iron, the skillet retains a distinct fishy smell, and imparts that Umami note to any other food cooked in it. Even after scrubbing and re-seasoning, that skillet is no longer used for anything but fish, or something being served with fish. I have also noticed that one of my anodized aluminum pans, used once to sear tuna steaks, has a much less pronounced fishy aroma while preheating, but does not change the taste of the food. I have heard of this also happening when using carbon steel, but I have no first hand experience with that. My family does not dispute me on the cast iron, but thinks I am bonkers when it comes to the anodized pan. I won't deny that they may be somewhat correct; however, I have a much stronger sense of smell than they do. For example, I can tell from the other side of the house, behind a closed door when when something in the oven is done -simply by the smell. My olfactory hypersensitivity notwithstanding, if you are using non-enameled cast iron, I would definitely line it with something. Either way, as Max points out, it makes clean up a breeze. The silicone will make the fish release cleanly from the heat preserving that beautiful finish without flaking off into the pan. Silicone can't take temperatures much higher than 400f/200c, so do heed the low-heat warning.

Aside: Silicone-lined aluminum foil? That is genius! I wish I cold find that state-side.

Answer 3

It is special foil (my friend gave me some!) and it is the best!! It absorbs fish smell. Put the foil in pan, fish on foil, put lid on pan. When done, throw out special foil. Fish smell goes out too—be careful flipping the fish to keep fish on the foil—and smell will be minimal.