Chop onions and cook in oil in an oven proof pan until clear, around 10 minutes.
Add garlic to pan and stir to combine. Cook for 1 minute.
Meanwhile, chop all veg into small chunks.
Throw remaining ingredients into the pan (besides breadcrumbs). Mix well, top with breadcrumbs.
Cover with foil and bake for 45 minutes. Remove foil and cook for another 15-20 or until water has been cooked out (a little liquid is fine).
This one pan pasta bake will work beautifully for leftovers the next day and while I haven’t tried it I would definitely freeze and think it would hold up fine.