In a medium bowl, add blue cheese and lemon juice; mash lightly with fork. Add apples, dried cranberries, pecans and horseradish; stir to combine.
Wash and separate leaves from core of each endive head. Spoon blue cheese mixture into each leaf. Place filled endive onto decorative platter and serve.
To toast pecans, place in a small skillet over medium heat. Shake skillet often until pecans are golden all over, about 4 minutes.