minecraft-assets/data/minecraft/recipes/coarse_dirt.json

{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    "DG",
    "GD"
  ],
  "key": {
    "D": {
      "item": "minecraft:dirt"
    },
    "G": {
      "item": "minecraft:gravel"
    }
  },
  "result": {
    "item": "minecraft:coarse_dirt",
    "count": 4
  }
}