Cut out any bones that may remain in the fillets. Mix the soy sauce and sugar in a resealable plastic bag and add the fillets. Seal the bag and toss it a bit to evenly distribute the marinade.

Refrigerate for at least 4 hours, or as much as 24.

To make Braised Red Onion, cook the bacon in a large saucepan until it renders and begins to crisp. Pour off half the fat.

Add red onions to the pan along with wine, soy sauce, thyme, brown sugar and vinegar. Cook over medium heat, stirring occasionally, until all the liquid boils away and the onions are tender, about 15 minutes. Refrigerate until fillets are ready to cook.

Toss panko or bread crumbs with parsley, thyme and melted butter in a mixing bowl.

When ready to assemble, preheat oven to 350°F. Reheat braised onions in the saucepan and spread them out in a large shallow baking dish. Lift the fillets from the marinade and arrange on top of the onions, skinned side down. Top each piece with an even coating of the crust mixture, gently patting it on with fingertips. Bake for 25 to 30 minutes, or until the fillets flake apart when nudged.

Turn the broiler to high and broil until the crumbs are golden brown.

Serve immediately with mashed, roasted winter squash, or braised winter kale.