Homemade baby food?

i've been giving my 7 month old jar baby food. she only eats half a jar at a time and its so expensive!!! i have a garden and i was wondering what veggies was okay to puree. i have corn, green beans, tomatoes, cubers, and okra. i know that's not a lot to choose from but i think i could buy organic produce from the grocery store cheaper than gerber! any advice?