It's actually possible for your dwarves to dine on Elf meat in an unmodded game, though it requires certain special circumstances and is quite limited:
Open the HFS pit, kill all of the demons, then reclaim the numerous pieces of human and elf meat in the bottom level. If you can't loot the lower chamber immediately (e.g. if the upper chamber contains burning charcoal, set on fire by SoF), then all you'll be able to save is whatever's stored inside cages.
in one of my previous fortresses, two of my dwarves were given this golden opportunity.
Do share what you did to make them edible. I'm considering making other races edible to dwarves in my game, just to avoid having piles of rotting corpses.
In version 39 you could butcher enemies, these days you can only butcher them only if u set ur ethics so and play it without saving / loading.
i made pets that mimic them in nearly every way so i can keep them.
here is the code for the domestic
[CREATURE:DWARVEN SLAVE]
[NAME:dwarven slave:dwarven slaves:dwarven]
[TILE:'s'][COLOR:0:0:1]
[PETVALUE:50]
[NATURAL][PET]
[LARGE_ROAMING][CAN_LEARN]
[COMMON_DOMESTIC][EVIL][BENIGN]
[PREFSTRING:beards]
[BODY:HUMANOID:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:HUMANOID_JOINTS:THROAT:NECK:SPINE:BRAIN:5FINGERS:5TOES:MOUTH]
[STOUT]
[MAXAGE:100:150]
[ATTACK:MAIN:BYTYPE:GRASP:punch:punches:1:2:BLUDGEON][ATTACKFLAG_WITH]
[ATTACK:SECOND:BYTYPE:MOUTH:bite:bites:1:1:GORE][ATTACKFLAG_CANLATCH]
[CHILD:12][CHILDNAME:dwarven slave child:dwarven slave children]
[DAMBLOCK:1]
[FAT:0]
[SIZE:6]
[CAVE_ADAPT]
[DIURNAL]
[STANDARD_FLESH]
[HOMEOTHERM:10067]
[LAYERING:50]
[SWIMS_LEARNED][SWIM_SPEED:2500]
[CREATURE:ELVEN SLAVE]
[NAME:elven slave:elven slaves:elven]
[TILE:'s'][COLOR:0:0:1]
[PETVALUE:50]
[NATURAL][PET]
[LARGE_ROAMING][CAN_LEARN]
[COMMON_DOMESTIC][EVIL][BENIGN]
[PREFSTRING:grace]
[BODY:HUMANOID:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:HUMANOID_JOINTS:THROAT:NECK:SPINE:BRAIN:5FINGERS:5TOES:MOUTH]
[NARROW]
[DAMBLOCK:-1]
[SIZE:7]
[ATTACK:MAIN:BYTYPE:GRASP:punch:punches:1:2:BLUDGEON][ATTACKFLAG_WITH]
[ATTACK:SECOND:BYTYPE:MOUTH:bite:bites:1:1:GORE][ATTACKFLAG_CANLATCH]
[CHILD:12][CHILDNAME:elven slave child:elven slave children]
[FAT:0]
[DIURNAL]
[STANDARD_FLESH]
[HOMEOTHERM:10067]
[LAYERING:10][MODVALUE:10]
[SWIMS_LEARNED][SWIM_SPEED:2500]
[CREATURE:HUMAN SLAVE]
[NAME:Human slave:Human slaves:Human]
[TILE:'s'][COLOR:0:0:1]
[PETVALUE:50]
[NATURAL][PET]
[LARGE_ROAMING][CAN_LEARN]
[COMMON_DOMESTIC][EVIL][BENIGN]
[PREFSTRING:stature]
[BODY:HUMANOID:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:HUMANOID_JOINTS:THROAT:NECK:SPINE:BRAIN:5FINGERS:5TOES:MOUTH]
[SIZE:7]
[MAXAGE:60:80]
[ATTACK:MAIN:BYTYPE:GRASP:punch:punches:1:2:BLUDGEON][ATTACKFLAG_WITH]
[ATTACK:SECOND:BYTYPE:MOUTH:bite:bites:1:1:GORE][ATTACKFLAG_CANLATCH]
[CHILD:12][CHILDNAME:Human slave child:Human slave children]
[FAT:0]
[DIURNAL]
[STANDARD_FLESH]
[HOMEOTHERM:10067]
[LAYERING:10]
[SWIMS_LEARNED][SWIM_SPEED:2500]
and here it is for ur mayday graphics if u use em.
[CREATURE_GRAPHICS:DWARVEN SLAVE]
[DEFAULT:DORFS:1:0:AS_IS:DEFAULT]
[CHILD:DORFS:2:0:AS_IS:DEFAULT]
[CREATURE_GRAPHICS:ELVEN SLAVE]
[DEFAULT:ELVES:0:0:DEFAULT]
[STANDARD:ELVES:1:0:AS_IS:DEFAULT]
[CHILD:ELVES:2:0:AS_IS:DEFAULT]
[CREATURE_GRAPHICS:HUMAN SLAVE]
[DEFAULT:HUMANS:0:0:DEFAULT]
[STANDARD:HUMANS:1:0:AS_IS:DEFAULT]
[CHILD:HUMANS:2:0:AS_IS:DEFAULT]
I use them that i can keep them as pets (slaves).
Train for war, arena matches, food or bait.
So many uses.