By the freshest meat you can. I find the meat at Costco to be very fresh. I have found a huge difference in the quality of the meat and grinding yourself lets you use more variety of meat. I have recently been using a combination of carrots, broccoli with a bit of cauliflower thrown in. Vary the vegetables you use.
Carrots are good for starting a cat on fresh foods as they are sweeter than most other vegetables.
Old fashioned oatmeal. At some health food stores, you will find the Kyolic Garlic with the vitamins. Get the powdered kind with red bone marrow. Super blue-green algae. If you get this from the health food store, be sure it is from Upper Kalmuth lake.