In small bowl mash eggs with 1/4 cup of the blue cheese dressing; season to taste with salt and pepper. Set aside.
Spread 8 of the toast slices with salad dressing. Arrange bacon on 4 of the slices; top with sliced tomato.
Spread the 4 remaining plain toast slices with egg mixture; top with onion and lettuce. Place one egg-topped toast on top of each bacon-topped toast. Top with remaining dressing-spread toast slices, spread side down. Secure with wooden picks; top with cherry tomatoes. Cut each sandwich in half using a sharp knife. Makes 4 sandwiches.