Sweet potato is a great first time baby food and definitely one of the easiest vegetable to prepare.
Preheat the oven to 190 deg C. Simply take one large sweet potato. Scrub it and prick it with a fork. Bake for about 45 mins or so (depending on the size), until it feels soft. Once cooked, all you need to do is split the potato and scrape out the flesh with a spoon. Hey presto - instant baby food, which doesn't even need pureeing! Just mash it lightly with a fork and you're ready to go. One large potato will give you about 3 or 4 portions at this early stage. Bake a few at a time and you've got a fortnight's supply!
Alternatively... you could peel the potato, then boil or steam it in cubes.
Other easy and affordable vegetables to try include Butternut Squash, Carrots, Courgettes and Potato.