For the salad thoroughly dry the escarole. This allows the dressing to stick and not just roll off the escarole.
Slice the apple with a mandoline. Top the escarole with apples and chopped almonds.
For the dressing place all ingredients except oil in a bowl and whisk to combine. Add olive oil in a slow stream while whisking constantly. Alternately, mix all ingredients in a blender. This will result in a thicker dressing.