Toast bread; set aside and keep warm.
In large nonstick pan over medium heat, cook bacon until crisp. Remove bacon and keep warm; reserve drippings.
For each sandwich, using about 2 teaspoons bacon drippings per egg, cook eggs in drippings until whites are set (completely coagulated and firm). Turn eggs over and cook an additional minute until yolks begin to thicken (no longer runny, but not hard).
Assemble each sandwich: Spread each of 2 slices of toasted bread with 1 tablespoon of mayonnaise. Top one slice with 2 slices tomato, 2 slices bacon, 1 egg, and 1 cup arugula. Top with remaining bread slice. Serve immediately.
*Arugula may be wilted down, if desired.
Yield: 12 sandwiches