Mix dry ingredients. In a large bowl, whisk together the dry ingredients: flour, sugar, baking powder, garlic powder, onion powder, mustard powder, kosher salt, and black pepper.
Add grated butter. Work it into the flour mixture with your fingers (or a pastry cutter) until all the butter is covered in flour and you have pea-sized lumps. Place the bowl in the refrigerator while you prepare the wet ingredients.
Mix wet ingredients. In a separate bowl, whisk together the coconut milk, egg, cheddar cheese shreds, and minced chives.
Combine. Pour the wet mixture into the dry ingredients. Mix together to form a shaggy dough. Transfer the dough to a lightly floured surface and knead it until it forms a ball.
Shape dough. Transfer the dough ball onto a baking sheet lined with parchment paper and shape it into an 8-inch disc either using your hands or a rolling pin. Cut the dough into 8 equal wedges using a bench scraper or sharp knife. Chill in the fridge while you preheat the oven to 400ºF/200ºC.
Bake. Brush the tops with a little coconut milk and sprinkle with flaky sea salt. Bake until the edges are lightly golden brown, 15-20 minutes. Let cool on a wire rack.