Grilled Chicken Thighs and Romaine with Dijon Vinaigrette

Name: Grilled Chicken Thighs and Romaine with Dijon Vinaigrette
Ingredients: Vegetable oil, for the grill; 2 tablespoons white wine vinegar; 1 1/2 teaspoons Dijon mustard; 1/2 teaspoon Worcestershire sauce; 1 small clove garlic, finely grated; Kosher salt and freshly ground black pepper; 1/3 cup extra-virgin olive oil; 1 tablespoon chopped fresh parsley; 1 tablespoon chopped fresh tarragon; 8 bone-in, skin-on chicken thighs (about 2 1/2 pounds); 1 head romaine, trimmed and quartered, root end attached