Wild Salmon and Potato Casserole with Citrus-Herb Vinaigrette

1 lb wild salmon fillet , skin removed
3/4 t salt
1/3 t pepper
1 lb new potatoes, sliced 1/4 inch thick
1/4 c olive oil
1 T olive oil
1 lemon, sliced into 1/4-inch-thick rounds
12 pitted black olives, such as niçoise or picholine
2 T lemon juice
1 T fresh orange juice
2 T chopped basil
1 t fresh thyme leaves

1. Preheat oven to 425 degrees F. Season the salmon fillet with ¼ teaspoon salt and 1/8 teaspoon pepper on both sides. Place the potatoes in a single layer in an 8 1/2- by 11-inch casserole. Drizzle
1 tablespoon of the olive oil over the potatoes and sprinkle with ¼ teaspoon salt and 1/8 teaspoon pepper; roast in the oven for 15 minutes.

2. Remove from oven and layer half the lemon slices over potatoes. Lay the fillet over the lemon slices, top with remaining lemon slices and olives, and return to oven. Reduce oven temperature to 250 degrees F and roast until salmon and potatoes are cooked through -- about 40 minutes.