Makes 6 servings
6 slices firm white sandwich bread
1/4 lb sliced bacon (about 5 slices)
6 Tbsp olive oil
1/4 cup finely chopped shallot
3 Tbsp Sherry vinegar
4 assorted medium heirloom tomatoes (2 lb total), cut into 1/4- to 1/3-inch-thick slices
30 small fresh basil leaves
1 1/2 oz blue cheese (preferably Maytag Blue), crumbled, at room temperature
Special equipment: a 3-inch round cookie cutter
Garnish: very small heirloom cherry or currant tomatoes
Cut 1 round from each bread slice with cookie cutter.
Cook bacon in a 10-inch heavy skillet over moderate heat until crisp, then transfer to paper towels to drain. Pour off bacon fat from skillet and reserve fat (do not clean skillet).
Heat 1 1/2 tablespoons oil in skillet over moderate heat until hot but not smoking, then toast 3 bread rounds, turning over once, until golden brown, about 3 minutes total. Transfer toasts to a rack to cool and season with salt and pepper. Toast remaining 3 bread rounds in 1 1/2 tablespoons more oil in same manner.
Cook shallot in 2 tablespoons reserved bacon fat and remaining 3 tablespoons oil in a small heavy saucepan over moderate heat, stirring, until softened, about 2 minutes. Add vinegar and simmer, whisking, until emulsified, about 1 minute. Season dressing with salt and pepper and keep warm, covered.
Crumble bacon. Arrange bread rounds on 6 plates and divide tomato slices among them, stacking slices and sprinkling some basil and bacon between slices. Sprinkle cheese and remaining basil and bacon over and around tomatoes.