Step 1Drain the pineapple, pressing on it with the back of a spoon, reserving all of the juice (1 1/4 cups). To make the salsa, combine the pineapple with the peppers, mint, cilantro and lime juice. Season to taste with salt and cayenne pepper. Place 1/2 cup of the salsa in a small bowl and set aside. Place the remaining salsa in a large mixing bowl.
Step 2Heat the olive oil in a saucepan over medium heat. Add the onion and cook until translucent, about 5 minutes. Pour in the reserved pineapple juice and bring to a boil. Stir in the couscous, cover and remove from the heat. Let stand for 5 minutes. Gently add the couscous to the larger bowl of salsa and combine. Season to taste with salt.
Step 1Place the scallops on a plate and season both sides with salt and pepper.
Step 2Heat the oil in a large skillet over medium-high heat. When the pan is very hot but not smoking, add the scallops. Sear for about 2 minutes. Turn and sear the other side for about 1 1/2 minutes. The scallops should be nicely browned and just starting to crack.
Step 3Divide the couscous evenly among 4 plates and top each with scallops. Divide the remaining 1/2 cup of salsa over the scallops for garnish.