You can use ready-made liquor like Cointreau of Drambuie, but also home made liquor.
A fantastic recipe for orange liquor can be found
here.
Melt 200 gram chocolate with 40 ml cream in the microwave.
Chop the walnuts very small. Add liquor and walnuts to the chocolate mixture and
put it in the fridge until it is a supple mass. Form small balls with the help of
2 teaspoons. Put these back in the fridge while you melt the rest of the chocolate with
1 tablespoon cream. Roll the balls through the melted chocolate. Put back in the
fridge for another hour. Dust with powdered sugar.