Combine onions, papaya and lime juice in a medium mixing bowl and gently mix well. Add Geoduck, cilantro, jalapeno and mix well. Place in refrigerator for 30 minutes.
Just before serving, toss mesclun salad with oil and season with salt and pepper. Place a portion of mesclun salad in the center of each plate, then top with a portion of the ceviche and serve.
Recipe courtesy of Karen Malody