In a small bowl, whisk together the garlic, lemon juice, Dijon, anchovy paste, pepper, Worcestershire and egg yolk (if using) and stream in the EVOO. Stir in the cheese.
Pour half of the marinade over the chicken and cover. Let stand for 30-60 minutes or refrigerate overnight.
Shake off the excess dressing and sauté in a hot skillet over medium-high heat until cooked through, about 12 minutes. Thinly slice.
To the same skillet, add the escarole and wilt it down. Add the remaining dressing and toss to coat. Reduce the heat and let the greens cook up a bit.
Pre-heat the oven to 375ºF.
Fill the bread shells with some greens and top with chicken and grated provolone and mozzarella cheeses.
Bake the pizzas until brown and bubbly.