I did the snapper en papillote as the last snapper course for our Mexi-Caj-ian dinner party this weekend and it it turned out great. Moreover, being able to prep in advance and cook at the last minute was a godsend for entertaining a bigger group.
First course was ceviche in individual cups with chips. I used my go to recipe base from Rick Bayless
https://www.foodandwine.com/recipes/classic-ceviche. This is a traditional Mexican preparation which has manzanilla olives in it, not something you see in most modern ceviches. Don't skip the olives. I did not use olive oil as I feel it detracts from the fresh taste, and I squeezed the juice of an orange on there before the final stir. I did not put the onions in with the fish while "cooking" in the lime, but instead just cut the onions a little smaller and added after the fish was done soaking in the lime. I left the fish in the lime for a little less than 3.5 hours before draining and adding the rest of the ingredients. Turned out great and got rave reviews. One of my favorite ceviches I've had, but there's nothing like cooking your own fish from the ocean so that's part of it.
(Second course I steamed some Alaskan king crab legs since they had a good deal at HEB)
Third course was a traditional blackened snapper. I had been wary of blackening smaller filets, but that didn't turn out to be an issue at all. Just needed a little less time between turns and a little closer watching. The bigger problem was that I've never done blackened fish for a group that big, which meant that I couldn't use cast iron. I used my stove top gas griddle on an oval burner which has worked great for searing steaks. I couldn't get it quite high enough to pull off the true blackened char crust on the first batch, although it was still quite tasty. Maybe I didn't let it heat up long enough because the smaller second batch got the crust I was looking for, although I tend to credit that to there being 2/3s less protein on the griddle. Tip here is to make sure the butter you dip the filets in isn't hot and that your fish is nice and cold when you dip it, as the butter sticks to the fish better if it's cold, and the butter (more than the spices) is where you get that good blackened crust and flavor from.
The fourth course was based on Fido's recipe above, what I have dubbed Miso En Papillote Nipponaise. I hit up the Asian grocery for some Miso, and also bought some interesting looking Mirin while I was there but, dangers of buying from the Asian grocery, it was overly sweet with corn syrup so I went with the Mirin I had in the pantry. I did not prep the night before, but I did prep several hours ahead of time which made it so much easier to pull off a multi-course meal for 12 while also making cocktails for everyone and just generally being a host.
I softened the veggies ahead of time in a wok w sesame, peanut, Chile oil , and garlic, cooking the carrots and onion a little longer, and then adding the zucchini, then the Bok Choi near the end. I splashed in some rice wine vinegar and soy sauce while cooking. Next time I think I would throw some minced ginger in at the beginning. Once the veggies were cooked I cooled before making the packets.
The miso glaze I just did to taste until I got the right mix of savory, heat, and sweet, along with a good consistency for spreading on the filets. It was primarily miso with some Chinese mustard, honey, and a little Mirin. I sprinkled a little Ginger powder and just a bit of 5 spice because I have a super-taster in the group who I like to keep guessing.
Assembling the packets was super easy, and I passed it off to my lovely sous chefs after making the first couple as exemplars. I used precut parchment 15" x 12" parchment sheets which was the perfect size. I could see them possibly being a bit small if the packets were the entire meal instead of just one of several courses.
Lay down the parchment, healthy tongful of cooked and cooled veggies, and then laid either one larger or two smaller filets on top of the veggies, and then spread the glaze on the filet before folding packets around the veggies. Filled two cookie sheets with packets and stuck in fridge until ready to cook. We went for 15 minutes at 400 and I took a packet out to check and it was perfect.
Because you're steaming in the packets I think the timing would be pretty forgiving, and the fact that different size filets turned out well bears that out.
The savory/umami of the miso with the lightly sweet of the honey and slight heat of the mustard was a great combo while still being delicate enough to not overwhelm the snapper. Great finish to the meal and being able to prep in advance made it all so much easier to pull off. And the presentation is fun as well.
Thanks to all, and especially Fido, for the recommendations.