In a small, oven-safe dish, make a bed of sliced onions to rest under the salmon. Season the salmon filets liberally on all sides with the Greek seasoning, and place skin-side down (if the skin is removed, this is the side with the gray ?bloodline?). Arrange the sliced lemon, and oregano sprigs on top of the fish. Pour the olive oil over the fish, allowing it to coat the onions at the bottom of the pan. Let stand 15-20 minutes at room temperature. Preheat oven to 400º F.

As oven preheats, make the minted creamy cucumbers. Mix the cucumbers and salt in a colander or strainer, over the sink or a bowl. Let stand 10-15 minutes. Squeeze gently, and blot dry on paper towels, or tea cloth. While the cucumbers are soaking, combine the lemon juice, mint, garlic, onion and yogurt in a medium bowl. Next, stir in the strained cucumbers. Add Greek seasoning to taste. Place aside in refrigerator while the salmon cooks.

Place the dish with the salmon on the bottom rack of the oven. Allow to bake until the salmon is just fully cooked, approximately 15-20 minutes. Fully cooked salmon is opaque, and firm when squeezed gently from the sides. Remove salmon from the oven, turn the oven off, and place the pita directly on the rack in the still-warm oven. Allow the salmon to rest for about 5 minutes while the pita warms. Remove and discard the lemon and oregano from the top of the salmon.

Place the salmon on one side of the plate, and top with some of the cooked onions. Place a mound of cucumbers next to the salmon. Cut the pita into eight slices and arrange next to the salmon and cucumbers. Or enjoy as a sandwich: Cut the pita in half to form two pockets, fill each half with layers of large flaked chunks of salmon, onions, and minted cucumbers. Enjoy!