ActuallyAdditions/src/main/resources/data/actuallyadditions/recipes/black_quartz_slab.json

{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    "###"
  ],
  "key": {
    "#": {
      "item": "actuallyadditions:black_quartz_block"
    }
  },
  "result": {
    "item": "actuallyadditions:black_quartz_slab",
	"count": 6
  }
}