Preheat oven to 400 degrees F.
In a food processor
combine bread, lemon zest, walnuts
until almost uniform in texture. Continue pulsing while drizzling in the olive oil
. Set aside.
Season fish with salt and pepper. Place 4 fillets in a single layer on a buttered 9 by 12-inch casserole
. In a small saucepan melt
4 tablespoons of butter and add the lemon juice
. Pour butter mixture over fish
, and sprinkle tops with bread crumb
mixture. Bake uncovered for 15 to 20 minutes.
Meanwhile, add the olive oil to a large skillet over medium heat. Infuse the oil with minced garlic, then add the Swiss chard
and saute until wilted, about 2 minutes. Season with salt and pepper, to taste. Serve hot with the sole.