1 large bulb fennel, trimmed of tough tops, reserving 2 tablespoons of the fronds
2 tablespoons extra virgin olive oil (EVOO)
1 medium to large yellow onion, thinly sliced
Salt and pepper
1 cup white wine
1 large or 2 medium Russet potatoes, peeled and very thinly sliced
1 cup chicken stock
1 1/2-1 3/4 pounds cod, cut into 4 portions (6-8 ounces each)
1/4 cup chopped flat leaf parsley (a couple of handfuls)
Crusty bread, to pass at table
Heat a large, deep skillet over medium-high heat and pre-heat oven to 425°F.
Cut tops off the fennel bulb. Reserve a few tablespoons of the fronds (the lacy dill-like greens) and chop. Quarter the bulb, then cut into each quarter on an angle to remove the core. Thinly slice the fennel.
Add EVOO, fennel and onion to the pan and sauté them, stirring frequently, about five minutes. Season with salt. Add wine and reduce by half. Add potatoes to the pan in thin layers, completely covering the fennel and onions, working all the way to the edges of the pan. Pour the stock evenly over the pan.
Season fish with salt and pepper. Arrange the fish on the potatoes. Bring the liquids to a bubble. Cover the pan and transfer to oven. Bake fish 15 minutes, until opaque, then uncover and bake for 2-3 minutes more. Transfer fish and vegetables to shallow bowls or dinner plates and garnish with parsley and fronds. Spoon juices down over the food. Serve with crusty bread for dipping.