Shred 5 of the radishes. Use a paper towel to blot out any excess water. Combine horseradish, ricotta cheese, pepper, and shredded radish in a small bowl. Preaheat a broil
er. Cut each bread slice
diagonally into fourths. Arrange bread in one layer on a baking sheet
. Broil for 2 minutes on each side or until toasted. Remove from heat and cool. Slice the remaining radishes thinly. Spread the ricotta cheese mixture onto each piece of bread and top with radish slices. Serve immediately, or store in a refrigerator, covered until ready to serve.