Crispy Potato Galette with Smoked Fish and Dill Crème

Name: Crispy Potato Galette with Smoked Fish and Dill Crème
Ingredients: 1/2 cup crème fraîche; 1 small shallot, minced; 2 tablespoons finely chopped dill; 2 teaspoons fresh lemon juice, plus more for brushing; Kosher salt and freshly ground pepper; 3 baking potatoes (1 1/2 pounds), peeled; 4 tablespoons unsalted butter, 2 tablespoons melted; 1/4 pound thinly sliced smoked salmon; 1/4 pound thinly sliced smoked sturgeon; Extra-virgin olive oil, for brushing; Freshly snipped chives and caviar, for garnish