1. Take a medium mixing bowl and mix crushed cereal, coconut, and walnuts. Keep the mixture aside.
2. Take a heavy saucepan and heat it. Add chocolate pieces in the pan and heat until melted.
3. Remove the saucepan from heat and add cereal mixture.
4. Take a greased, deep muffin pan and press about 1/3 cup mixture firmly onto bottom and sides. This is done to form a shell.
5. Repeat the same process with the leftover cereal mixture. Make 6 shells in all.
6. Chill all the shells until firm.
7. Add a large scoop of peppermint ice cream in every shell.
8. Cover the pan lightly and freeze until firm.
9. Make sure to remove the dish from the freezer a few minutes before serving.
10. Also, remove every stuffed shell from muffin pan carefully.