Preheat the oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a large bowl, whisk together flour, baking soda, baking powder, and salt until evenly distributed.
Cut the cold, cubed butter into the dry mix until the mixture resembles coarse meal with pea-sized bits.
Stir in the grated cheddar and chopped herbs, tossing to coat in the flour mixture.
Pour in the buttermilk and mix with a wooden spoon until a shaggy dough forms; avoid overmixing.
Turn the dough onto a lightly floured surface and knead gently five times, just until it comes together.
Pat the dough into a 7-inch round on the prepared baking sheet and score a deep “X” on top with a sharp knife.
Bake for 20–25 minutes, until golden brown and hollow-sounding when tapped on the bottom.
Notes
I found that grating the butter while frozen helps create those flaky pockets in the crumb.Tent the loaf loosely with foil if the crust browns too quickly, based on my afternoon bake experiments.Let the bread cool completely before storing to maintain a crisp crust, as I discovered on test batch number four.