What is the legal test for a jury in a case involving heat of passion and unreasonable self-defense?

A trial court has a sua sponte duty "to instruct fully on all lesser necessarily included offenses supported by the evidence. . . . [I]n a murder prosecution, this includes the obligation to instruct on every supportable theory of the lesser included offense of voluntary manslaughter . . . ." (People v. Breverman (1998) 19 Cal.4th 142, 148-149.) "[A] trial court errs if it fails to instruct, sua sponte, on all theories of a lesser included offense which find substantial support in the evidence. On the other hand, the court is not obligated to instruct on theories that have no such evidentiary support." (Id. at p. 162.) "In a murder case, . . . both heat of passion and unreasonable self-defense, as forms of voluntary manslaughter, must be presented to the jury if both have substantial evidentiary support." (Id. at p. 160.) " 'Substantial evidence' in this context is ' "evidence from which a jury composed of reasonable [persons] could . . . conclude[ ]" ' that the lesser offense, but not the greater, was committed." (Id. at p. 162.)