In a large mixing bowl, mix the jalapeno with the onion, lime juice, lemon juice, mango, papaya, cilantro and extra-virgin olive oil. Season mixture with salt and pepper, then stir in the scallops immersing them completely in the marinade. Cover and refrigerate for at least 8 hours, preferably overnight. (The acids in the marinade will "cook" the scallops.)
Peel cucumbers and cut into 1/4-inch thick slices. Strain scallop mixture and spoon onto cucumber disks. Top with 1/8 teaspoon of caviar.
Recipe courtesy Robert Irvine with Brian O'Reilly, Harper Collins Publishers, 2006