Break Down:

The Biome condition allows for the recipe to either happen in a specific biome, or outside said biome. It has two fields, one required: biome, which is the name, and one optional: inBiome, which defaults to true, and determines whether the recipe needs to be in, or outside of the biome.


    "type": "base:biome",
    "biome": "minecraft:plains",
    "inBiome": true