[cypher]

I would stick to veg rather than fruit as fruit is too acidic for them to have much of it.
Green veg are always good, so broccoli, often a favourite with hams, small amounts of lettuce, cabbage or pak choi are fine too, things like peas (frozen are fine) are usually enjoyed too, cucumber or courgette, peppers are all liked by most.
I would go easy on the baby food unless he needs it for meds as they should really be eating their mix mostly, giving too much soft food means their teeth don't wear down as much as they should which can just lead to more problems.
A few small pieces of nut, flax/linseed, sunflower or pumpkin seeds make good treats, millet sprays are usually enjoyed too but his mix has quite a lot of millet already so maybe not such a good idea to give more.

This is my (almost!) complete list of veg that I use, excuse the bit about diabetes prone species which doesn't apply to you, I'm just copying & pasting the list I keep handy!

Safe veg, those marked * are relatively high in sugar so only feed to diabetes prone species as an occasional treat if at all.
Asparagus
Basil
Broccoli
Brussels sprouts
Common or red clover
Cabbage, green or red
Carrot*
Cauliflower
Celery
Chard
Coriander
Courgette
Cress (not mustard & cress as commonly sold together)
Cucumber
Dandelion leaves & flowers
Endive/chicory
Green beans/runner beans
Kale
Pak choi/Bok choi
Parsley
Peas/mange tout/sugar snap/snow*
Peppers, any colour
Potato/sweet potato cooked only*
Radicchio
Spinach
Squash/pumpkin*
Swede
Sweet corn/baby corn*
Turnip