Working in batches, cook the bacon in a large pan over medium-low heat until crisp, 5 to 10 minutes. Transfer to a paper towel-lined plate to drain.
While bacon is cooking, prepare yogurt dill sauce: Combine the yogurt, dill, chives and lemon juice in a small bowl; season with salt and pepper to taste. Cover and chill until ready to serve.
Season salmon with salt and pepper, to taste. Place in the same pan you used for the bacon, using leftover bacon grease as cooking oil. If you used a leaner bacon, add 1 Tbsp. extra-virgin olive oil to the pan.
Cook salmon until opaque, about 4-5 minutes per side. Remove from pan and allow to rest before slicing into portions for the sandwiches.
Spread the yogurt dill sauce on 4 slices of bread and top with the lettuce. Add the salmon, tomato, and a few strips of bacon and top with another slice of bread.
Recipe adapted from: www.themountainkitchen.com