For the cauliflower: Preheat the oven to 400 degrees F.
Heat a large pot of generously salted water over medium-high heat and prepare an ice bath with a few pinches of salt. When the water comes to a boil, blanch the cauliflower florets until just cooked, about 2 minutes. Immediately shock in the ice bath to stop the cooking. Drain and set aside.
For the fish: Combine the ground fennel seed, olives, cherry tomatoes, celery, lemon juice, shallot, fennel, zucchini, a drizzle of good finishing oil, red pepper flakes and some salt in a medium bowl.
Cut 2 large sheets of parchment paper into heart shapes and brush the paper with olive oil, leaving a 1-inch border around the edges. Arrange half of the vegetable mixture on one piece. Top with a piece of fish, then top with two lemon wheels and some fennel fronds. Repeat with the remaining vegetables, fish, lemon wheels and fronds on the other piece of parchment. Fold and crisply crease each heart into a half-heart, enclosing the fish and vegetables inside but leaving a small opening on one end. Pour 2 tablespoons wine into the openings on each packet, then finish enclosing the packets tightly. Place the packets on a rimmed baking sheet and bake 7 to 8 minutes.
For the cauliflower: Meanwhile, coat the bottom of a cold, large skillet with a decent amount of olive oil. Add 3 cloves garlic and 1 anchovy fillet. Put the skillet over medium-high heat. Cook until the garlic is golden brown and fragrant, about 3 minutes. Remove and discard the garlic from the skillet. Add the panko and cook, stirring in the warm oil, until golden and toasty, 3 to 5 minutes. Add the parsley, toss to combine and transfer the mixture to a plate.
Wipe out the skillet, add more oil to coat, and place back over medium-high heat. Add the Calabrian chile paste, remaining 2 cloves garlic and 1 anchovy fillet and stir to combine. Cook until the garlic is golden brown and fragrant, about 3 minutes. Remove and discard the garlic from the skillet. Add the capers and blanched cauliflower. Gently mix to coat the cauliflower and cook until warmed through, 2 to 3 minutes.
Plate the cauliflower and sprinkle with the panko breadcrumbs. Serve with the fish en papillote.