Epicurious asked chef Tom Colicchio for this recipe from 'Wichcraft, the sandwich shop in his growing collection of Craft restaurants. It's the perfect way to use up leftover Thanksgiving turkey — and a good excuse to roast a turkey any time of year. To create those leftovers, try [Tom Colicchio's Herb-Butter Turkey](/recipes/recipe_views/views/233118).
02In food processor or blender, purée yolk, garlic, mustard, and vinegar until smooth and creamy, 1 to 2 minutes. Combine oils, then, with motor running, slowly drizzle into processor until completely emulsified, about 2 minutes. (If aïoli gets too thick, add a small amount of warm water, 1 teaspoon at a time.) Sprinkle in salt, pepper, and pepperoncini, cover with plastic wrap, and refrigerate until ready to use.
03Preheat oven to 350°F.
04In large, heavy skillet over moderate heat, cook 6 slices bacon, turning occasionally, until crisp, then transfer with tongs to paper towel–lined plate to drain. Repeat with remaining 6 slices. Set aside.
05Slice each ciabatta in half and place on large baking sheet. Place 4 ounces turkey on each of four ciabatta bottoms, then spread onion relish over meat. Lay 3 slices bacon on each of 4 ciabatta tops. Transfer baking sheet to oven and toast until bacon is crispy and edges of ciabatta turn light golden brown, about 5 minutes (the turkey does not have to get hot). Remove from oven and transfer bacon to other side of ciabatta, laying on top of onion relish. Divide avocado slices between sandwiches, placing on top of bacon. Spread aïoli evenly across each ciabatta top, close sandwiches, slice each in half, and serve.