In a large, nonreactive bowl, combine the lemongrass, ginger, garlic, scallion greens, soy sauce, sesame oil, and honey and whisk well. Add the shrimp and toss to coat. Marinate in the refrigerator for 15 to 30 minutes.
Skewer the shrimp, scallion whites, and red bell peppers onto skewers in whatever order you like. There should be 4 to 6 shrimp per skewer.
Place the skewers on a flat plate and drizzle with peanut oil. It is not necessary to salt the skewers because soy sauce has so much salt in it. Place the shrimp skewers on the grill and cook about 3 minutes per side, or just until the shrimp curls, turns red and does not appear clear at all. Be careful not to overcook.
Place the whole radicchio leaves around the edge of a platter. Mound the chiffonade radicchio and watercress inside the leaves and around the platter. Remove the skewers from the grill and place on the bed of greens. Squeeze the juice of a lime over the shrimp.
If using wooden skewers, be sure to soak them in water for at least 30 minutes before placing on the grill.