Yes thats what par boiling is but tbh its better to steam....preserves more of the nutrients. Usually only needs a few mins depending on the veg. We roast a lot too, seems to prefer that.
My lo is a day older than yours and we're doing baby-led weaning, so no purees, fingers foods form the start. So far he has:
Roasted/steamed sweet potato, carrot & butternut squash
Steamed broccoli & courgette
Sweetcorn
Gluten/wheat free pasta
Nectarines
Grapes
Cucumber
Banana
Kiwi
Organix sweetcorn crunchy rings and carrot sticks, plus baby rice cakes
Organix soft rusks
Avocado
yoghurt
bread (gluten/wheat free)
tuna
He's only been eating for a month so thats it so far, but introducing new stuff all the time!