Look for precooked eggs, such as Eggland's Best, in the dairy section of the supermarket.
Serves 4 (serving size: 1 sandwich)
1. Cook bacon in a medium saucepan over medium-high heat 3 minutes or until crisp. Remove bacon from pan; crumble. Place bacon in a large bowl. Stir in onions and next 5 ingredients (through salt). Gently stir in eggs.
2. Arrange 1/2 cup arugula on each of 4 bread slices. Top each serving with 1/3 cup egg mixture and 1 bread slice.