Here is one of my favorite liver recipes: pan fried baked liver with dry white wine, fresh sage and garlic!
It will shrink, that’s normal. Quickly brown the liver on one side for 3 minutes. Then flip it over.
Bake the liver for another 3 minutes. Cooking time depends on how you want the liver to be on the inside. I like mine quite pink. Once seared on both sides, place it on a plate and cover with tinfoil. Put it aside until needed later. Add extra olive oil to the pan (don’t wipe it clean) and turn the heat to medium. Add the sliced garlic and black peppercorns to the pan.