Bread and Shrimp Skewers with Romaine Salad

Name: Bread and Shrimp Skewers with Romaine Salad
Ingredients: 3/4 pound large peeled and deveined frozen shrimp (about 24), thawed; 2 garlic cloves, minced; 1 tablespoon grated lemon zest, plus 2 tablespoons lemon juice; 4 tablespoons extra-virgin olive oil; Coarse salt and ground pepper; 5 ounces crusty bread, cut into 1-inch pieces (3 cups); 1 hard-cooked egg yolk, mashed; 1 teaspoon Dijon mustard; 1/4 cup grated Parmesan, plus more for serving; 2 large hearts romaine lettuce, leaves separated