PaperMC/paper-server/nms-patches/net/minecraft/world/item/crafting/IRecipeComplex.patch

--- a/net/minecraft/world/item/crafting/IRecipeComplex.java
+++ b/net/minecraft/world/item/crafting/IRecipeComplex.java
@@ -3,6 +3,11 @@
 import net.minecraft.core.HolderLookup;
 import net.minecraft.world.item.ItemStack;
 
+// CraftBukkit start
+import org.bukkit.NamespacedKey;
+import org.bukkit.inventory.Recipe;
+// CraftBukkit end
+
 public abstract class IRecipeComplex implements RecipeCrafting {
 
     private final CraftingBookCategory category;
@@ -25,4 +30,11 @@
     public CraftingBookCategory category() {
         return this.category;
     }
+
+    // CraftBukkit start
+    @Override
+    public Recipe toBukkitRecipe(NamespacedKey id) {
+        return new org.bukkit.craftbukkit.inventory.CraftComplexRecipe(id, this);
+    }
+    // CraftBukkit end
 }