[cypher]

They do need to have food available at all times so you are doing that right, for trying to wake him earlier you could top up the bowl or scatter a little food each day you could also make it treat time & give him his veg at that time each evening (spinach is fine but it is good to slowly work up to daily veg but using a good variety so something different as many days as possible) you could also try giving something really smelly like a mealworm! That usually tempts them out.
I wouldn't give yogurt drops as they are just sugar & fat really, Russian hams are prone to diabetes so avoid sugars, honey or fruit as treats or in food.