minecraft-assets/assets/minecraft/advancements/recipes/tools/flint_and_steel.json

{
  "parent": "minecraft:recipes/root",
  "rewards": {
    "recipes": [
      "minecraft:flint_and_steel"
    ]
  },
  "criteria": {
    "has_flint": {
      "trigger": "minecraft:inventory_changed",
      "conditions": {
        "items": [
          {
            "item": "minecraft:flint"
          }
        ]
      }
    },
    "has_the_recipe": {
      "trigger": "minecraft:recipe_unlocked",
      "conditions": {
        "recipe": "flint_and_steel"
      }
    },
    "has_obsidian": {
      "trigger": "minecraft:inventory_changed",
      "conditions": {
        "items": [
          {
            "item": "minecraft:obsidian"
          }
        ]
      }
    }
  },
  "requirements": [
    [
      "has_flint",
      "has_the_recipe",
      "has_obsidian"
    ]
  ]
}