1/3 cup thinly sliced red onion
2 tablespoons apple cider vinegar
8 slices turkey bacon
1 avocado, halved and pitted
1/2 cup nonfat plain Greek yogurt
Kosher salt and freshly ground pepper
8 slices whole-grain bread, lightly toasted
8 small leaves romaine lettuce
1 tomato, cut into 8 slices
12 ounces sliced low-sodium deli turkey breast
1/2 small cucumber, sliced
Toss the onion with the vinegar and 2 tablespoons water in a small bowl. Let stand 15 minutes, then drain. Meanwhile, cook the turkey bacon as the label directs until crisp.
Mash the avocado with the yogurt in another small bowl until smooth. Season with salt and pepper.
Lay 4 slices of bread on a cutting board and spread with half of the avocado-yogurt mixture. Top with the lettuce and tomato and season with salt and pepper. Add a layer of turkey breast, bacon, cucumber and red onion. Spread the remaining avocado mixture on the remaining 4 bread slices and top the sandwiches.