Instructions
Step 1
To a medium pot set over medium heat, add the mirin, vinegar, lemon juice, sugar, chile flakes, 12 of the peppercorns, the juniper berries, 2 of the bay leaves, the cinnamon, ginger, and 1 cup of water. Season to taste with salt and cook, stirring frequently, until the salt and sugar are dissolved, 3–5 minutes. Transfer the brine to a large bowl and refrigerate. Return the pot to the stove.
Step 2
Add the celery stalks, wine, the remaining peppercorns and bay leaves, and 8 cups of water to the pot and season to taste with salt. Cover and bring to a boil, then turn the heat to medium-low and simmer until the celery is tender, 18–20 minutes. Using tongs, transfer the celery to the brine. To the poaching liquid in the pot, add the shrimp and cook until just pink and opaque, 1–2 minutes. Transfer the shrimp to a small bowl to cool, then peel, devein, and add to the brine. Cover with plastic wrap and refrigerate for at least 1 hour and up to 12 hours, tossing the mixture once halfway through.
Step 3
Cut the celery on the bias into bite-size pieces and place on a large platter. Strew the shrimp and reserved celery leaves on top, season to taste with salt, drizzle with oil, and serve cold or at room temperature with lemon wedges.