You're "plain" food is great, much healthier than the average mixed, prepared food. I eat "plain" food as well as my dd has a milk protein allergy and she's bf. It makes it easier when you start feeding more solid table food, don't have to worry about the salt and sugar added in prepared food as you control it yourself.
I started to give dd protein at 8 mths (as suggested by our ped), I give her beans, meat, chickpeas, (lentils). The beans or chickpeas I puree on their own. I actually do most veggies on their own as well (then cube and freeze) this way I select 2-3 items to mix together for new flavours ie. chicken and mango, chickpeas and spinach, etc. I've also added pasta, I found one that is in very tiny star shapes that doesn't have to be blended or cut up, in addition we've done rice. My ped (and the local bfing clinic) told us to give cereal for breakfast and dinner (to total about 10 tbsps in a day) so that dd gets her required iron, they said they often see babies low in iron but if your lo is ff then he may already be getting enough.
Other items I've done (in addition to the ones you've done) are mango, peaches, avacodo (very high cals and nutrients), blueberries, zuchini, spinach, green beans, turkey, beef, boiled egg yolk, yams, orange pepper, tomatoes (dd loves the peppers with tomatoes and pasta). One thing my ped said was to avoid the jars of mixed food with meat and opt for the jars of just meat because there isn't enough protein in the mixed jars- there's so much filler instead. I do jars when we go away weekends so I had asked about jarred food.
So, basically, we do-
breakfast- cereal and I add 2 tbsps fruit
lunch- protein 2 tbsps, veggie 2 tbsps, starch food 1 tbsp (I do potatoes, yams, pasta, or rice here)
dinner- cereal and I add 2 tbsps fruit or veggie
1-2 snacks if needed could be yogurt or cheese based (my dd's are bf snacks due to her allergy)