minecraft-assets/data/minecraft/recipe/dried_kelp_from_smelting.json

{
  "type": "minecraft:smelting",
  "category": "food",
  "cookingtime": 200,
  "experience": 0.1,
  "ingredient": "minecraft:kelp",
  "result": {
    "id": "minecraft:dried_kelp"
  }
}