Cal. Health & Saf. Code § 33458
As an alternative to the separate public hearing required by Sections 33451 and 33454, the agency and the legislative body, with the consent of both, may hold a joint public hearing on the proposed amendment. The presiding officer of the legislative body shall preside over such joint public hearing. Prior to such joint public hearing, the agency shall submit the proposed changes to the planning commission as provided in Section 33453. Notice of the joint public hearing shall conform to all requirements of Section 33452. The joint public hearing shall thereafter proceed by the same requirements as are provided in Sections 33450 and 33454 to 33455, inclusive.
When a joint public hearing is held where the legislative body is also the agency, the legislative body may adopt the amended plan with no actions necessary by the agency, even as to the recommendations required of the agency by Sections 33454 and 33455.
Ca. Health and Saf. Code § 33458