"If you didn't grow up in a coastal town in the South, you might never have eaten pickled shrimp with your Thanksgiving dinner. But since you can use frozen shrimp in this recipe, it might be time to try. Briny and a bit spicy, this pickled shrimp is full of flavor. You can make this dish the day before the feast for a faint pickle taste or leave them in the refrigerator for a week before, which means you'll bring something with huge personality to the table. Either way, this might become a tradition for your family. Good for a week."
Bring a large pot of water to a boil over high heat. Add shrimp and 1 tablespoon salt; reduce heat to low and cook until shrimp are pink, about 2 minutes. Drain the shrimp and transfer to the bowl of cold water until chilled, 3 to 5 minutes. Drain again.
Combine remaining 1 tablespoon salt, lemon zest and juice, parsley, pickling spice, garlic, and red pepper flakes in a bowl. Pour in olive oil and whisk together to make the pickling oil.
Fill a resealable glass jar with shrimp and shallots in 4 alternating layers. Pour the pickling oil on top, submerging all contents. Put on the lid and refrigerate for 24 hours.