Fish to clean, gut.

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Cut into half rings onion, tomato and lemon.

Fish RUB with salt, pepper, seasoning. Two sides make deep incisions. In each incision to put in the lemon, tomatoes and onions (alternate).

Lubricate on both sides of fish with mayonnaise.

Spread on foil. Above and below the fish, put the coarsely chopped cilantro.

Wrap the fish, put on a baking sheet and place in preheated oven to 200 degrees. Since I was quite a big fish, I baked the fish for 40 minutes, then the foil unwrapped and josepeculo another 15 minutes.

I want to give a recommendation. I cooked on the original recipe author did incisions. I have not quite managed to lay out the cuts the filling. It is better to make it easier. Fish immediately cut into portions (head and tail do not throw), put it in foil and then put between slices of onion, lemon and tomato (you can circle for each). Yes, in this case tomato, lemon and onion need to cut it slices. Then to create a fish with the head and tail. So and wrap in foil. The fish turned out well, very tasty! I'm generally a fan of mackerel hot smoked, but now I will cook it myself and the only way.