For the court bouillon: Combine the white wine, peppercorns, thyme, bay leaves, dill, serranos, lemons and fennel in a medium saucepan. Bring to a boil over medium-high heat, then add 8 cups room temperature water and the shrimp. Put the squid and the scallops in a fine-mesh strainer and lower them directly into the court bouillon. Gently poach the seafood until cooked through and tender, about 15 minutes. Remove the seafood to a plate, strain the court bouillon into a bowl, and then add the seafood back to the court bouillon. Add a few ice cubes to cool the liquid down. Refrigerate for 30 minutes.
For the seafood salad: In a large mixing bowl, combine the lemon zest and juice, olive oil, oregano and black pepper. Whisk well. With a slotted spoon, remove the chilled seafood from the court bouillon and add it to the bowl along with the cherry tomatoes, olives, pepperoncinis and bell peppers. Toss well.
Arrange a bed of arugula on a large serving platter. Mound the seafood salad on top and garnish with the feta and capers. Serve immediately.
Before slicing, check the squid tubes for any unremoved quills. If you find any, just pull them out and discard.