1 pound baking potatoes, peeled and cut into 2-inch chunks
3 large egg yolks
Finely grated zest of 2 lemons, preferably Meyer lemons
2 tablespoons plus 1 teaspoon extra-virgin olive oil
1 1/2 teaspoons salt
3/4 cup all-purpose flour
1/2 cup low-sodium chicken broth
1 stick plus 2 tablespoons unsalted butter, cut into pieces and chilled
1 tablespoon fresh lemon juice
Salt
Snipped chives, for garnish
Bottarga, for garnish (optional)