If you doubt whether your older baby gets enough iron from breastmilk alone, I think your question was reasonable, as the strongest "official" rationale for introducing solids after 6 months is the alleged "inadequate iron" in breastmilk at some point after six months (this is difficult to refute), and meat and fish is one of the easiest ways for babies to increase their iron intake (chicken and fish is the third group of first foods recommended by LLL:
). However if your baby thrives as you mentioned you should not be too concerned.
I give DS strips or bits of chicken and fish in several ways: preloaded chopsticks (mentioned in previous posts) or preloaded spoons; or spread in congee (or your porridge) and macaroni; or just let DS grasp the strips (recently). If I knew how to make pizzas I would definitely spread into them too. I never consider myself doing any "trick" because this is also the usual way I eat meat and fish. By the way, DS loves chicken and fish! (But I always tell him "this is fish congee", "this is chicken macaroni")
Besides meat and fish, you may also try egg yolk. It is also an excellent source of iron (and other nutrients). Of course some vegetables, beans, dried fruits and algae are good sources of iron too (when eating together with Vitamin C [i.e. fresh fruits and steamed vegetables]).
p.s. DS is still breastfed 6~7 times a day + 2 or 3 "meals".