Beat cream cheese, horseradish sauce, onion and Ranch dressing mix together at medium speed with an electric mixer until blended; set aside.
Cut 24 rounds from toasted bread using a 3-inch cutter. (Select a cutter close to the size of the tomato slices.) Reserve bread trimmings for another use, if desired.
Spread 1 side of each round evenly with cream cheese mixture; top with 1 tomato slice and 2 egg slices. Sprinkle evenly with dill and pepper. Makes 12 servings. Enjoy!