Take it from someone who also created a 'picky eater' - stop giving little extras in the food. I know you want him to eat, but sometimes our pups go through phases for no particular reason other than they're just not hungry. He will eat when he is hungry, no need to worry. He looks healthy and happy, so you shouldn't panic over it.
Suki has gone literally 3 days without touching her food - and then the next day she will devour both meals.
Don't drive yourself crazy thinking about what to put in his food bowl next. If he's doing well on his current kibble - just wait it out and let him decide when to eat.
One thing that did help us during the 'picky' times (without resorting to making silly concoctions) was a treat ball. But instead of treats, we put her kibble in the ball. By making meal time into a game, it made it more interesting for her and most times, she'd finish what was inside the ball and then go finish the remainder of the kibble we left in her bowl.