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