Get the stew set up on the fire. Then send two villagers to the lavender flower in the northern part of the graveyard. Then put one villager down at the orange flower in the south part of the map. After the water and food have been added check the health indicators of each villager. The ones that are low take over to the stew and let them eat.This will restore all of the health of the ones that need it. If you are short of a doctor to cure the ones that are sick this will also restore their health.