Potato and Blue Cheese Tart

Name: Potato and Blue Cheese Tart
Ingredients: 1½ (7½ ounces/213 grams) (7½ ounces/213 grams) all-purpose flour; 1 teaspoon table salt , divided; 10 tablespoons unsalted butter , cut into ½-inch pieces and chilled; 6-7 tablespoons ice water; 4 ounces (113 grams) cream cheese; 2 ounces (57 grams) blue cheese , crumbled (½ cup), divided; 1 ounce (28 grams) Parmesan cheese , grated (½ cup), divided; 2 tablespoons extra-virgin olive oil; 2 teaspoons Dijon mustard; 1 1/2 teaspoons minced fresh rosemary , divided; 1/4 teaspoon pepper; 1 large egg , separated; 1 pound russet potatoes , peeled and sliced ⅛-inch thick; 1 shallot , sliced thin