src/main/resources/assets/mekanismtools/recipes/obsidianchestplate.json

{
  "result": {
    "item": "mekanismtools:obsidianchestplate"
  },
  "pattern": [
    "* *",
    "***",
    "***"
  ],
  "type": "forge:ore_shaped",
  "key": {
    "*": {
      "ore": "ingotRefinedObsidian",
      "type": "forge:ore_dict"
    }
  }
}