This was a specialty of the now-closed Pittman House Restaurant in Dallas, Texas.

1 cup mayonnaise
1/2 cup minced scallions
2 tablespoons brandy
1/4 teaspoon coarsely-ground black pepper
18 slices toasted whole-wheat bread
Leaf lettuce
12 ounces crabmeat, picked over well
    to remove any shells
Tomato slices
12 slices slab bacon, cut in half,
    cooked crisp and drained
2 avocados, sliced

In a small bowl, combine the mayonnaise, scallion and brandy, mixing well. For each sandwich, spread three pieces of bread with a portion of the mayonnaise mixture. Cover the first slice of bread with lettuce leaves, 2 ounces of crabmeat, and one or two tomato slices. Add the second slice of bread, and top with the four half-slices of bacon, a layer of avocado slices, another tomato slice or two, and more lettuce. Cover with the third slice of bread, secure the sandwich with wooden picks, if you like, and slice it in half.

Serve the sandwiches immediately.