Rinse leaves and blot with paper towel to dry.
Combine balsamic vinegar and orange juice in a small pan. Cook over high heat until volume of liquid reduced by half (about 4 minutes). Set aside to cool.
Blend together cream cheese and blue cheese.
Place about 1 teaspoon of cheese mixture on each endive leaf. Add a few pieces of chopped walnuts and drizzle with the balsamic-orange reduction.
Could also use cucumber slices or red bell pepper slices