Preheat oven to 400°F (200°C). Line 2 baking sheets with parchment paper.

In a large bowl, whisk together flour, baking powder, and salt. Using your fingers, rub cold butter into flour mixture until butter is pea-size. Make a well in center.

In a small bowl, whisk together 4 eggs (200 grams), ½ cup (120 grams) milk, and ½ cup (16 grams) chives; add to flour mixture. Using one hand like a claw, mix together just until combined. Add up to remaining ½ cup (120 grams) milk, 1 tablespoon (15 grams) at a time, if needed. (Dough should be wet and sticky.)

Turn out dough onto a lightly floured surface. Lightly flour top of dough, and pat to ½-inch thickness. Using a 2½-inch round cutter, cut 14 scones from dough, rerolling scraps as needed. Place 1½ inches apart on prepared pans. (For alternative shaping method, see PRO TIP.)

In another small bowl, whisk remaining 2 eggs (100 grams). Brush tops of scones with egg wash.

Bake until golden brown, 14 to 15 minutes. Remove from pan, and let cool completely on wire racks.

In a medium bowl, whisk together yogurt, sour cream, lemon juice, and remaining 1 to 2 tablespoons (2 to 3 grams) chives. Serve scones with chive cream and salmon. Garnish with oil and dill, if desired. Scones are best served the same day.