Place the eggs in a single layer in a pot or saucepan. Fill a large bowl with ice water. \nCover the eggs with cold water, at least 1-inch above the eggs. Bring the water to a boil over high heat. Once boiling, remove from the heat and cover the pot. Let sit for about 10 minutes, then immediately plunge into the ice water bath. Let sit in the ice water for about 10-15 minutes before peeling. \nMeanwhile, in a small mixing bowl, whisk together the mayo, Korea sauce, lemon juice and ½ teaspoon kosher salt. \nPeel and dice the eggs into ¼-inch chunks. Transfer to a mixing bowl along with the celery, scallions and half of the Korea-spiced mayonnaise (reserving the other half for serving). Mix until well combined. \nSpread a smear of Korea mayo onto your toasted bread. Top with a spoonful of egg salad. Sandwich together and enjoy!