I really like this product, espeically after eating cornbread in the States. It's really easy to make, although I never use the little cardboard 'baking tray' you get with it - I always use a greased baking tray or muffin tin. All you need to do is add an egg and some milk as per the instructions (you can either mix it in the bag provided or put everything in a bowl), mix, transfer to a tray, and then pop it in the oven.
I would advise to add a little extra milk, as cornbread is quite 'gritty' due to the cornmeal, and unless you smother it with butter it can be quite dry to eat (I found the extra milk helped keep it moist, although adding it was purely by accident, I didn't read the instructions properly! I had to leave the mix in the oven a little longer, but check it like you would do a cake and see if a knife comes out clean!).
All in all a great product, very tasty and fills you up, nice for a lazy weekend breakfast with a good brew!