What's the best gift joe has ever received?是什么从句

定语从句
从句部分是Joe has ever received，前面省略了一个引导词that。从句是修饰gift的定语

定语从句

宾语从句。

定语从句。
中心词是 Gift， joe has ever received作为定语从句修饰Gift。
Gift在从句里做宾语。