Grilled Whole Fish with Sweet Peppers

steps

1. Preheat a grill to high heat for at least 15 minutes.
2. Prepare the fish for grilling by checking for gills and using scissors to cut them out if they are not already removed. Use the scissors to trim off excess parts that will burn, like fins and the end of the tail fin. Rinse the fish under cold water and pat it dry.
3. Meanwhile, in a medium bowl, gently whisk together the vinegar, olive oil, and lemon juice. Set the dressing aside.
4. “Close” the scales of the fish by running your fingers with the grain of the scales, in the direction that water flows, so that they feel smooth rather than rough. This will help to get an even better sear on the skin. Use a brush to paint the top side of the fish all over, including the head and tail, with a thin layer of mayo, making sure to paint the scales “closed.” Season it aggressively with kosher salt and black pepper.
5. Grease the grill grates with neutral oil. Prepare to lay the fish on the grill, leaving space to grill the peppers simultaneously on another part of the grill. Lift the fish by the tail and lay it, mayo side down and head first, directly on the grill, angling it ever so slightly away from you as you lay it on the grates. Paint the other side (now the top of the fish) with mayo and season it aggressively with kosher salt and black pepper.
6. Restrain yourself from checking the fish at all for the first 5 minutes—unless it is really smoking and burning (in which case reduce the heat, or, if you absolutely must, gently transfer it to a colder spot on the grill). After 5 minutes, you can gently lift up the tail and check to see if the fish has started to gain color. You’re looking for a deep golden-brown color with some black marks, which will usually take 6 to 8 minutes of cooking.
7. Once the first side of the fish is finished, use two spatulas (or a spatula and tongs) to gently flip the fish, almost as if you are rolling the fish toward you in one delicate, supported move. Once the fish has flipped, once again don’t even think about checking it for another 5 minutes. After that, you can begin to look at the color on the bottom. Continue cooking the fish until the first side (now on top) is at an internal temperature of 130°F, about 8 minutes.
8. Once it is cooked, flip it back once more and grill the other side (this will also recrisp the other side) until it, too, is at 130°F, about 1 minute more. Note that for a whole fish, it is better to go over than under: 135°F or more is totally fine. The bones and all make a whole fish a lot more forgiving. Once the second side is done, use both spatulas to lift the fish and lay it on a serving plate. Don’t worry if there is a little bit of tearing of the flesh or breakage— that’s natural. Just do your best to be as gentle as possible when lifting the fish from the grill.
9. While the fish is cooking, place the peppers in a large bowl with just enough olive oil to coat. Season them with kosher salt and toss to combine. Place the peppers on the grill, ideally in a grill basket. Grill them, turning frequently, until they are mostly charred, about 4 minutes. (If your grill does not have space for both, simply grill the peppers after the fish is finished.)
10. Once the peppers are finished charring, return them to the large bowl and add half of the dressing, tossing them to combine. Add the herbs and toss until well mixed, seasoning with a touch more kosher salt.
11. Pour the dressed peppers and their liquid on top of the fish, allowing the peppers and sauce to flow over to the sides of the plate. Serve immediately, with the remaining dressing and flaky sea salt on the side.