Minecraft Wiki: Adding a Simple Recipe

package net.minecraft.src;

public class mod_myMod extends BaseMod
{
    public void addRecipes()
    {
        ModLoader.addRecipe(new ItemStack(Item.diamond, 2), new Object[] { "DDD", "DDD", "DDD", 'D', Block.dirt});
    }

    public void load()
    {
        this.addRecipes();
    }

    public String getVersion()
    {
        return "Version 1.0";
    }
}