For the escarole salad: Set a small saute pan over medium heat; coat with olive oil. Add the prosciutto, and cook until crispy. Remove from the pan and set aside.
Combine the hazelnuts, pecorino and parsley in a food processor; pulse until coarsely chopped. In a bowl, toss together the escarole, hazelnut mixture and some pickled red onions. Dress with some red onion pickling liquid and olive oil. Season with salt, and garnish with crispy prosciutto.
For the chicken Milanese: Set up a standard breading station in three wide, deep plates. Fill one plate with the flour, a second with the beaten eggs, and a third with the panko and Parmesan. Sprinkle the chicken breasts with salt. Using one hand for dry things and one hand for wet things, take each piece of chicken through the breading procedure: Dredge lightly in the flour, then in the egg wash, and then through the breadcrumbs. Lay the breaded chicken on a baking sheet and refrigerate for at least 1 hour.
Pour olive oil into a large saute pan until it reaches a depth of about 1/2 inch--better a little more than a little less. Bring the oil to medium-high heat. Test by flicking flour or breadcrumbs into it; if it doesn't sizzle, WAIT! When the oil is hot, test it again by dipping the edge of a piece of chicken; the oil should sizzle gently. In batches, cook the chicken on both sides until crispy and a lovely golden brown, 4 to 5 minutes. (Do not crowd the pan or the chicken will become very greasy and soggy.) When the chicken comes out of the oil, drain on paper towels and sprinkle with salt. If you like, keep the chicken warm in a low oven while the rest of the chicken is cooking.
Place the chicken serving plates and top with escarole salad.
In a small bowl, combine the red wine vinegar with 1/2 cup cold tap water. Stir in the salt, sugar and hot sauce. Add the sliced onions, and let sit for at least 1 hour.