Preheat the oven to 375 degrees F and grease a standard loaf pan (8x4 inches).
In a large bowl, combine the flour, baking powder, baking soda, and salt and whisk to combine.
Add the grated butter (grated cold on a box grater), and use your fingertips or a pastry cutter to cut in the butter until it is the texture of wet sand with pea-sized clumps of butter, then toss in the cheese.
In a separate bowl, whisk together the egg and buttermilk, then pour into the bowl with the dry ingredients.
Mix briefly but thoroughly until just combined, then transfer the mixture to the prepared loaf pan.
Bake for 35-40 minutes until golden brown with a clean cake tester.
