Ever stopped to ask, "Why?"
I usually find it in the meat aisle here, but haven't bought it for ages since I can't stand the texture of it. Good luck getting your iron levels up, I usually get the Spatone water out when I need to do this. Get it from the healthfood store (Healthpost.co.nz is cheapest generally) and just add it to juice.
The way I cook the liver actually makes it quite palatable for me. Fry it (cut into small pieces) with mushrooms, lots of chopped garlic and a pinch of salt. Then afterwards mix it with hot chili sauce. I serve it inside a wrap alongside salads from the garden (kale, cress etc), cream cheese and tartare. One lamb liver lasts four wraps.
What all grows in your garden!?