Vets usually discourage owners from homemade
Why? Because most owners know next to nothing about their own nutrition, let alone trying to make something balanced for their pet. The most common issue I see with a lot of homemade diets is no calcium, just muscle meat, maybe some sort of starch or a veggie or two. A true diet encompasses all necessary vitamins and minerals (taurine is especially needed in cats and is found in heart muscles usually).
I know most people who think homemade cat food refer to this website: http://www.catinfo.org/ All of this is made by a veterinarian dedicated to cats and she includes a recipe for a raw diet as well. I researched into cooking the raw diet since none of my cats touch raw anything but wasn't sure if the amino acid balance would be thrown off.
You have to pay either for the supplement or the non-supplement recipe, but a site for cooked homemade diets is run by UC Davis: https://secure.balanceit.com/ I used it for a couple of months but neither of my cats were gungho about the diet. They're very finicky in that respect.