How to Make It
Cook bacon in a medium skillet over medium, stirring occasionally, until almost crisp, about 6 minutes. Add leek, butter, and garlic. Cook, stirring often, until leek is tender and bacon is crisp, 2 to 3 minutes. Remove from heat; stir in crackers, parsley, kosher salt, pepper, lemon zest, and paprika.
Preheat broiler to high with oven rack in center of oven. Spread coarse sea salt in an even layer on 2 rimmed baking sheets. Nestle oyster shells into salt. Top oysters evenly with cracker mixture (about 2 teaspoons each). Broil, 1 baking sheet at a time, until topping is golden brown, 1 to 2 minutes. Serve oysters with lemon wedges.