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

{
  "type": "minecraft:crafting_shaped",
  "category": "misc",
  "key": {
    "#": {
      "item": "minecraft:brick"
    }
  },
  "pattern": [
    "# #",
    " # "
  ],
  "result": {
    "item": "minecraft:flower_pot"
  }
}