What do you carry for those "just in case" situations?

Hypothetical situation: You're on an infrequently traveled trail, in the winter when a snow storm moves in stranding you for 3 days. Your shelter,sleep system and stove/cooking system are adequate for the conditions and you are near a good water source but your food bag is empty or nearly so.
Do you have an emergency food pouch? What's your emergency food of choice? a few MountainHouse type meals? some homemade dehydrated delicacy? some of those emergency Daltrex bars? a jar of peanut butter? maybe a bag of buckwheat (like Lars, the YouTube, Survival Russia guy likes so much)?

Extra points go to suggestions that are light weight but calorie dense.
Not so concerned with the balanced nutritional value, assuming you're only gonna be stranded for three days.

any thoughts?