Preheat the grill to a moderate heat, about 350 degrees F (180 degrees C).
Slice the pears into quarters and remove the core and seeds.
In a plastic bag add the pears, demerara sugar, turmeric, nutmeg, and salt. Shake well to fully coat the pears, then rest while the grill heats.
Spray the grill with the oil, then add the pears. Grill until there are caramelized sugar grill marks then turn, repeat until the three sides of the pear are cooked.