4 ounces thick-cut pancetta, diced into 1/8-inch cubes
¼ cup sherry vinegar
2 egg yolks
2 tablespoons prepared horseradish, plus more if needed
1 tablespoon Dijon mustard
½ tablespoon coarse salt
¼ teaspoon freshly ground black pepper
1 cup blended oil (half vegetable, half olive oil)
24 fresh, shucked oysters; Wiley Points and Wellfleets are good for this because their plumpness can stand up to grilling), with half shells reserved and rinsed
1 small bunch fresh chives (about 10), sliced into ½-inch pieces
1. Heat a large sauté pan over medium-high heat. When the pan is hot, add the pancetta, reduce the heat to medium, and cook until the pancetta is very crispy, about 7 minutes. Transfer the pancetta to a plate lined with paper towels to drain. Once cool, chop the cubes in to a very fine dust. Set aside.
2. To make the aioli: Combine the vinegar, egg yolks, horseradish, mustard, salt, and pepper in a blender. With the blender running, pour the blended oil through the opening in the lid in a slow, steady stream until a thick sauce forms. Adjust the seasoning and add extra horseradish for a more intense flavor. Cover and refrigerate for up to 5 days.
3. To make the oysters: Preheat the grill (gas or charcoal) to medium-high. Arrange the oysters on half shells in one layer on the grill grates. Close the lid and grill until the oysters are just warmed through, 2 to 3 minutes.
4. To serve, arrange the grilled oysters on a platter. Top each oyster with a dollop of the aioli, a sprinkle of pancetta dust, and a few pieces of chive.