POACHING LIQUID: Add the water, peppercorns, garlic, parsley, bay leaves, shallot, and kosher salt to a large stock pot and bring to a boil. Once boiling, using a slotted spoon, carefully remove all of the poaching ingredients from the water.
POACH: Carefully add the shrimp into the hot water. Turn the stove off, cover with a tight fitting lid and let the shrimp cook for 2-5 minutes, 2-3 minutes for medium shrimp, 3 minutes for large, and longer for jumbo. They should be opaque and curled into a ‘c’ shape when done. Prepare the ice water bath while the shrimp poach.
ICE WATER BATH: While the shrimp poach, add 2 cups of ice and 2 cups of water into a large heatproof bowl. When the shrimp are done, carefully use a slotted spoon to transfer them to an ice water bath to cool them down quickly.
SALAD DRESSING: In a medium bowl, combine the mayo, lemon zest, 3 tablespoons lemon juice, celery, chives, dill and a few cracks of black pepper in a bowl with ½ teaspoon umami seasoning or kosher salt. Whisk together.
ASSEMBLE: Once the shrimp are cooled down, add them to the dressing and mix. Then add the thinly sliced cucumbers. Taste the salad and adjust with more umami seasoning or kosher salt as desired. Serve immediately or cover and let the flavors meld together for 1 hour.