Tuna salad meets BLT in this keto-friendly mashup. Hang on to that oil in the tuna can for a flavor bonus.
Cover the eggs with about an inch of water in a medium pot. Bring to a boil, remove from the heat, cover and let stand for 8 minutes. Drain and submerge in ice water. When cool enough to handle, peel the eggs and chop.
Meanwhile, cook the bacon in a large nonstick skillet over medium heat until golden and crisp, about 4 minutes per side. Remove to a paper towel-lined plate. Crumble into bite-size pieces.
Whisk together the mayonnaise, sour cream, lemon zest and juice, celery, reserved tuna oil, ¾ of the scallions, ¼ teaspoon salt and several grinds of pepper in a medium bowl. Add the tuna and ¾ of the bacon and egg and gently fold together (do not overmix). Season with additional salt and pepper if needed.
Sprinkle the tomato slices with salt and pepper.
Double-up the lettuce leaves and fill each with some tuna salad. Tuck in a tomato slice. Sprinkle with reserved scallions, bacon and egg.