
Ingredients
1/2C Whole milk
2T Sugar
1 1/4oz Envelope active dry yeast (about 2 1/4 teaspoon)
1/2C Buttermilk
1/2C Onion, finely chopped
2T Finely chopped fresh dill
2t Dill seeds
1 1/2t Kosher salt
2 1/2C AP flour plus more
4T Unsalted butter, melted, divided, plus more for bowl and parchment paper
Process
Gently heat milk until warm to the touch (an instant-read thermometer should register 120°F–130°F).
Add sugar and yeast and whisk to combine.
Add buttermilk; let sit until yeast starts to foam, 5–10 minutes.
Combine onion, fresh dill, dill seeds, salt, and 2 1/2 cups flour in a large bowl.
Stir in milk mixture and 2 tablespoons butter, adding more flour as needed (dough will initially be fairly wet), until a sticky dough forms.
Turn out onto a lightly floured surface and knead until dough is smooth and elastic, about 5 minutes.
Transfer dough to a lightly buttered bowl and cover with plastic wrap.
Let rise in a warm, draft-free area until doubled in size, about 1 hour.
Punch down dough and let rise until doubled again, about 1 hour.
Punch down dough and, using a pastry scraper or a sharp knife, divide into 12 pieces.(70-75g each)
Line a baking sheet with parchment paper and lightly butter top.
Cupping your hand over and using your palm, roll each piece of dough on work surface into a ball and place on prepared baking sheet, spacing at least 2″ apart (you need to leave enough room so that they’re not touching after they’ve risen).
Brush tops with remaining 2 tablespoons butter and cover loosely with plastic wrap; let rise until almost doubled in size, 20–30 minutes.
Meanwhile, preheat oven to 400°F.
Bake rolls until puffed and deep golden brown on the tops and bottoms, 15–20 minutes. Transfer to a wire rack and let cool slightly before serving.
DO AHEAD: Rolls can be made 3 hours ahead. Reheat before serving, if desired.