Bacalhau a gomes de sa (codfish with potatoes casserole)

2 pounds salt cod
6 tablespoons olive oil, plus extra for drizzling
2 large yellow onions, sliced
4 cloves garlic, minced
pinch nutmeg
white pepper, to taste
4 medium waxy potatoes, boiled, cooled, peeled and cut into 1/4-inch slices
8 hard-boiled eggs, halved, for garnish
Portuguese olives and chopped parsley, for garnish

1. Rinse the cod under cold running water to remove any surface salt. Place the fish pieces in a large nonreactive pot, cover with water and refrigerate (covered) for 24 hours, changing the water several times.
2. Pour off the water, refill the pot with clean water and gently boil the cod until it flakes easily with a fork, about 7 to 10 minutes (or longer), depending on the thickness.
3. Meanwhile, heat 3 tablespoons of the oil in a large skillet over medium heat, and saute the onions until barely brown. Add the garlic and cook a minute more. Set aside.
4. Drain the cod and let cool. Flake it into a large bowl and remove any bones or bits of skin. Add the onion-garlic mixture, nutmeg, white pepper and remaining olive oil, and toss lightly. Pack the mixture into well-oiled 9-x-13-inch ovenproof casserole dish. Cover the codfish with the potato slices.
5. Lightly oil a cookie sheet, place it over the casserole and invert. Carefully remove the casserole dish to keep the cod mixture intact. Bake in a preheated, 400 F (200 C) oven for 20 to 30 minutes, or until cod is lightly toasted.
6. To serve, cut a square of cod and center it on a plate. Drizzle with additional olive oil to moisten. Garnish with 2 egg halves, several olives and some parsley.