Sheet Pan Spring Chicken Dinner

Name: Sheet Pan Spring Chicken Dinner
Ingredients: 1/4 cup plus 2 tablespoons extra-virgin olive oil; 2 tablespoons fresh lemon juice; 1 tablespoon fresh dill, finely chopped; 1 tablespoon fresh parsley leaves, finely chopped; 4 cloves garlic, grated; 8 bone-in, skin-on chicken thighs (2 1/2 to 3 pounds); 1 pound baby rainbow carrots, tops trimmed; Kosher salt and freshly ground black pepper; 1 pound rainbow fingerling or baby potatoes, halved lengthwise; 1 bunch scallions, cut into thirds; 3 tablespoons Dijon mustard; 1 tablespoon extra-virgin olive oil; 2 tablespoon fresh dill, finely chopped; 2 tablespoons fresh parsley, finely chopped