In a small pot over medium heat, toast almonds, garlic, and fennel seeds in olive oil. Once garlic is browned, add chile flakes, a few turns of black pepper, rosemary, and parsley. Remove from heat and let cool slightly.

Cut the head off, removing the front pectoral fins. Make a small incision on either side of the dorsal fin. Pull to remove along with the cartilage beneath it. Trim off the lower fins. Cut the tail off, going through the bone, right at the adipose fin (the small fleshy fin on the top rear of the fish). Butterfly the fish, starting from the inside of the belly cavity and cutting directly along the bones, but do not cut through the skin on the back on the fish. Do this on both sides of the spine and remove. If you’ve messed this up at all, that’s totally OK. Scrape or trim off any meat attached to the back bone and reserve. Using a thin, flexible knife, cut the rib bones and discard. Using tweezers, pull out the pin bones from the flesh. You should have 2 fillets still attached to the skin and attached to each other by the skin that lay in a flat sheet. Cutting lengthwise, slice off a piece roughly half the thickness of each fillet and reserve. (A good fish store will be able to do the butterfly cut for you.)

*If using a salmon fillet, trim off the tail end so the fillet is roughly the same size on the head and tail sides. Make sure that all the bones are removed. Cutting lengthwise, slice off about half the thickness of the fillet and proceed as instructed above.

Season all the fish lightly with salt. Spoon about half the garlic-parsley paste and rub into the fillets attached to the skin. Toss the reserved pieces of fillet with the remaining paste and mix gently to coat. Place the fillet pieces back on the fish in a roughly even layer. With the fish in front of you horizontally, take the top fillet and roll it over the bottom fillet so that it forms an even Yule Log of fishy deliciousness. Using kitchen twine, gently tie it as you would a roast so it maintains its shape. Gently transfer to a roasting rack with the seam side down.

Place in a 300° oven and cook until the internal temperature on an instant thermometer reads 128–130°, about 30–40 minutes. Once cooked, remove from oven and change the oven to high broil. Use a spoon to collect any of the rendered fat and oil from the tray and spoon over the skin to baste. Once the broiler is smoking hot, place the fish back under for 1–3 minutes until the skin is nice and crispy. Remove from the oven and let rest a few minutes. Use your sharpest knife (maybe even a serrated knife) to cut the fish into medallions or on a slight bias. Serve with roasted vegetables as desired.