The halibut in this dish stands up on its own, with just a tad of butter added to the end. It lets its counterparts do most of the work, with the crispy Brussels sprouts providing texture and the citrusy yuzu beurre blanc adding a burst of fresh flavor.
Season the halibut with salt and pepper. Preheat the oven to 350 degrees. In a 1-quart sauce pot, heat the wine and yuzu over medium low heat until reduced by ½. Heat up two 12-inch sauté pans over medium-high heat. Add a light coating of canola oil and the pancetta to one of the pans. When the pancetta begins to brown and release its fat, add the Brussels sprouts. Add 2 tablespoons or so of canola oil to the other pan. When it just begins to smoke, add the halibut to the pan and sear for 3-4 minutes or until golden brown. When the Brussels sprouts begin to brown, add a few pieces of the butter to the pan. Season lightly with salt (the pancetta can be quite salty) and reduce heat to medium. Flip the fish over and add a couple pieces of butter to the pan. Finish for about 6 minutes in the oven, until the fish in cooked through.
Pull the yuzu/wine mixture from the heat and slowly whisk in 1 stick of butter, adding 1 piece at a time. If the pan cools too much, briefly return it to the heat. Finish with 1/2 of the chives and a pinch of salt. Deglaze the Brussels sprouts with the chicken stock and reduce to a glaze. Finish with the remaining chives.