Bring 2 liters (4 liters for 4 servings) salted water to a boil in a large pot. Add orzo, and cook for 6-9 minutes or until al dente. Strain and add back to the pot. Dress with 1 tbsp. (2 tbsp. for 4 servings) olive oil. Keep warm off to the side.
Wash and trim ends off of cucumbers. Slice into 1/2 inch rounds, and place in a mixing bowl along with red onion. Season well with salt, sugar, half of the lemon juice and a pinch of red pepper flakes to taste. Mix well and set aside.
Prepare Yogurt Sauce:
Wash and chop dill. Add to a small bowl, along with yogurt, garlic, and remaining lemon juice. Season to your liking with salt and pepper. Set aside.
Pat steelhead fillets dry using paper towel. Season both sides well with salt and pepper. When the orzo is cooked, heat 1 tbsp. (2 tbsp. for 4 servings) oil in a large skillet over medium-high. Place steelhead in hot oil and cook for 1 1/2 to 3 minutes per side until outside is golden and crisp and fish flakes easily with a fork.
Pour yogurt sauce over cooked orzo and stir together. Season to taste with salt and pepper.
Divide orzo between serving dishes with a side of marinated cucumber salad. Place fish on top of orzo. Enjoy!