Warm the milk to 110°F. In the bowl of a stand mixer fitted with a dough hook, stir the warmed milk with the instant yeast and sugar. Let sit 1–2 minutes.

Add the flour, sourdough discard, beaten egg, 1 Tablespoon chopped herbs, 1 teaspoon kosher salt, and 1 teaspoon garlic powder to the mixer.

With the mixer on low, slowly pour in the 2 Tablespoons melted butter.

Increase speed to medium and mix until a shaggy dough forms.

Turn the dough onto a smooth work surface. Knead by hand until the dough is smooth and slightly tacky, about 3–4 minutes. Add flour or milk 1 Tablespoon at a time if needed.

Place dough in a large greased bowl. Cover with plastic wrap and let rise 60–90 minutes, until doubled.

While the dough rises, make the butter topping: in a small bowl, combine the 7 Tablespoons softened butter, 1 Tablespoon chopped herbs, 1 Tablespoon garlic powder, and 1/2 teaspoon kosher salt. Mix until smooth. Reserve 1 Tablespoon of this mixture for brushing the baked loaf.

Grease a 9×5-inch loaf pan and set aside.

After the first rise, turn dough out and divide into 12 equal pieces (about 55 g each). A kitchen scale helps for even stacking.

Flatten each piece into a rough 4-inch circle. Spread 1–2 teaspoons of the butter mixture on each piece. Fold in half like a taco and place in the pan, fold-side down. Repeat until all pieces are in the pan.

Cover the pan with plastic wrap or a clean towel. Let the dough rise 30–45 minutes until puffed but not higher than the pan edges.

Preheat oven to 350°F.

Bake 30 minutes. Tent with foil and bake 5–10 more minutes until deep golden and the internal temperature reaches about 200°F.

Remove from oven. Brush with the reserved tablespoon of butter mixture and sprinkle flaky sea salt on top.

Let cool in the pan for 10 minutes, then serve warm.