buy a huge piece of new york or rib eye about 5-10kg (costco has it or local butcher/farmer)
make sure it is marbled. the more marbled (fat) the better and also healthier
lot of fat is essential
cut into steaks of your liking. if not very hungry, you can cut the steak in half.
once a week liver or other organ meat is needed because it has some nuitirients you will not get from beef.
here is a good start to watch for your wife:
https://www.youtube.com/live/CZ-qwRGNgjo?feature=share