Heat the grill to high.
Combine the seafood in a large bowl, toss with the olive oil and season with salt and pepper.
Grill the shrimp for approximately 1 minute per side, remove and place on a platter. Grill the squid bodies and tentacles for 2 to 3 minutes per side, remove from the grill and slice crosswise into 1/2-inch thick rings and place on the platter with the shrimp. Grill the scallops until golden brown on both sides and just cooked through, about 1 1/2 to 2 minutes per side, place on the platter.
Whisk together the lemon juice, garlic, honey, jalapeno and extra-virgin olive oil in a large bowl. Add the seafood, chili flakes, onion, celery, olives, oregano, and 1 tablespoon of the parsley and toss to combine. Season with salt and pepper. Cover and refrigerate for 30 minutes. Stir in the remaining parsley just before serving. Place the mesclun greens on a large platter and top with the seafood salad.