Step 1

In a small bowl, whisk together the vinegar, shallot, mustard, and 1/2 tsp. each salt and pepper. Whisk in the oil in a slow and steady stream until incorporated.

Step 2

Put the nuts in a zip-top bag, force out the air, seal the bag, and break the nuts with a meat pounder or a heavy skillet into uneven pieces.

Step 3

In a large bowl, toss the apples with 1 Tbs. of the dressing. Add the escarole, cheese, onion, parsley, and hazelnuts. Toss with the remaining dressing and serve.