Yes you could try a 7pm routine

Putting new hamster mix out each day is quite important as they strangely seem to ignore food unless it's freshly put out. So they will leave food in a bowl once it's been there for a day. They won't starve as they have a hoard to snack from. But I'm guessing it's part of the foraging instinct, to "forage" the new food each day and ignore anything that isn't new. What I tend to do is empty the bowl every couple of days but always put a new heaped dessertspoonful out each day (on top of the old food one day then empty the bowl the next day - if you use a bowl). Or scatterfeed half of it and put half in the bowl.
It seems like a waste of food, but they don't eat that much and hamster food isn't massively expensive

As it's been three weeks then yes I would start trying to tempt him out. It can take a lot of patience at first though as it could take another few weeks of gentle taming before he can actually be handled! But you can start with a stroke now and then which is something. Have linked the taming article below
Also do you have a photo of his set up? We might be able to suggest the odd tweak that might encourage him out more.
Hand taming a hamster can make life with your hamster very rewarding. Suddenly they will sit on you to be stroked or even go to sleep on you, and will be very easy to handle. It can take a bit of time and patience initially.
www.thehamsterforum.com