2 medium fennel bulbs (sometimes called anise; 1 1/2 lb total), stalks cut off and discarded, and fronds reserved for garnish if desired
1 1/2 lb large boiling potatoes
3 large garlic cloves, minced
1 teaspoon salt
1/4 teaspoon black pepper
6 tablespoons extra-virgin olive oil
2 lb skinless cod fillet (1 inch thick), cut into 6 portions
Garnish: chopped fennel fronds or fresh flat-leaf parsley
Accompaniment: lemon wedges
Special equipment: a Japanese Benriner* or other adjustable-blade slicer; a 3-quart shallow baking dish (2 inches deep)
Directions
Preheat oven to 400°F.
Cut fennel bulbs crosswise into 1/16-inch-thick slices with slicer. Peel potatoes and cut crosswise into 1/16-inch-thick slices with slicer.
Transfer fennel and potatoes to baking dish and toss with garlic, salt, pepper, and 4 tablespoons oil. Spread vegetables evenly in dish and bake, covered with foil, in middle of oven until just tender, 25 to 30 minutes.
Season fish with salt and pepper and arrange on top of vegetables. Drizzle with remaining 2 tablespoons oil and bake, uncovered, until fish is just cooked through, 12 to 15 minutes.
Available at Asian markets, many cookware shops, and Uwajimaya (800-889-1928).
