When Po came to live with me he had two food issues. Firstly, he was an extremely picky eater. Secondly, he would never eat in his cage. It ended up with Po sharing from Esther and Chris' plates and him picking out the food he wanted to eat.
Now I am NOT criticising Esther and Chris, this is what worked for them and they are maybe a bit softer then I am (mwahahahahah!)

I knew within a couple of days that Po sharing my food from my plate just wasn't going to work so I completely stopped that and only gave him food in the cage.
I gave him whatever fresh food the others were having when I left for work in the morning, seed in his playstand bowl from about 11.30am until they go back in their cages at about 5pm and Harrisons Course pellets with a few Nutriberries in his cage for the rest of the day.
For a couple of days he barely ate at all as he didn't like eating in the cage (that was the very hard part and I very nearly gave in) then for weeks he only ate the Nutriberries in the cage and barely touched the Harrisons.
Then I bought some Harrisons High Potency Fine for him to try instead of the Course, he picked at it now and again.
Well I'm delighted to report that for the last couple of weeks he's shown more and more interest in the Harrisons and now rushes to the bowl to eat it!

Mojo and Shinda love their Harrison HP Course and Henry likes the Hagen pellets and his Nutriberries. So, other than the seed in the Nutriberries (and the seed I sprout) my house is now a seed-free house! I won't be buying any more loose seed!
Food routine now is fresh food (whatever veg/fruit/sprouted seed/pulses etc I'm feeding that day) only in their bowls when I'm out at work for about four hours in the morning.
Hagen pellets (which they all like) in their playstand bowls for their several hours out in the afternoon.
When they go back in their cages in the evening Mojo and Shinda have their Harrisons HP Course and one Nutriberry each, Henry has his Hagen and four Nutriberries (my aim will be to cut down the Nutriberries and increase the pellets and eventually get him onto Harrisons too but for now he eats only a small amount of Hagen, preferring the Nutriberries) and Po has his Harrisons HP Fine and one Nutriberry!
I also put a bit of chopped, raw sweet potato (which they all love) on top, it's dry and doesn't make the pellets soggy.
I'm so pleased they are all getting the perfect balance of vitamins and minerals without the hit-and-miss of using liquid/powder supplements and are all eating their fresh food in the morning

Po now loves his Harrisons so much that he always flies up to the side when I'm getting the bowls ready to go back in the cages!
Video of Po enjoying his Harrisons...
Video of Po eating his Harrisons in the cage (raw sweet potato and parsley leaves on top of the pellets which he also loves)...

