*To check whether salmon is done, press the back of a spatula onto the salmon to feel for firmness. If it feels spongy, it is not fully cooked.
1/2cupfresh dill, chopped, divided
3-4green onions, chopped
Cut the cucumber lengthwise and remove the inside seeds. Cut into smaller sections and add to a food processor with the yogurt, cilantro, green onions, and 1/4 cup dill. Puree until smooth, and season to taste with salt and pepper. Refrigerate for 2 hours or overnight to allow the flavors to steep.
Lay the salmon fillets in a 9×13-inch baking dish. Drizzle the melted butter over the salmon. Squeeze the fresh lemon over the salmon. Season with salt and pepper. Sprinkle with 1/4 cup fresh chopped dill.
Cover the dish with foil and refrigerate for 30 minutes.
Preheat oven to 325 degrees and bake the salmon, covered, for about 30 minutes. If the salmon is thick, bake for 15 minutes and then check for doneness (*using back of spatula technique).
Serve salmon with cucumber herb sauce on the side.