What is the test for instructing a jury on an uncharged offense that is less serious than a charged greater offense?

"A criminal defendant has a constitutional right to have the jury determine every material issue presented by the evidence, and an erroneous failure to instruct on a lesser included offense constitutes a denial of that right. To protect this right and the broader interest of safeguarding the jury's function of ascertaining the truth, a trial court must instruct on an uncharged offense that is less serious than, and included in, a charged greater offense, even in the absence of a request, whenever there is substantial evidence raising a question as to whether all of the elements of the charged greater offense are present." (People v. Huggins (2006) 38 Cal.4th 175, 215.) "This venerable instructional rule ensures that the jury may consider all supportable crimes necessarily included within the charge itself, thus encouraging the most accurate verdict permitted by the pleadings and the evidence." (People v. Birks (1998) 19 Cal.4th 108, 112.)