Ah, yes, got to beware while pg. But for afterwards here goes....
Good thing is recipe is easily adaptable to any size, hence no measurements
Heat over to 180 degrees or equiv
Take liver and remove all the larger tubey bits and slice liver into thinish strips (1cm or so)
Dust it all over with well seasoned flour and put to one side.
Finely slice as many onions as you think appropriate for amount of liver and fry in olive oil over low heat until all golden and translucent but not brown. Remove onions and place in casserole dish.
In same pan fry liver in batches in a little oil so is brown all over. You do not have to cook it through, just brown it, it may still ooze a bit of blood but ignore this.
Put in casserole with onion as you go.
When finished, put a mug full of water in to the frying pan and scrape all the brown bits off the pan and empty this into casserole dish, add extra water so that it just cover liver and onion mix.
Now take as much bacon as you think appropriate. I like to use unsmoked back, but smoked streaky is nice too. Roll it up tightly and tuck it alongside liver so is semi exposed at top of pan. Put a lid on the lot and stick in over for at least an hour, though is very forgiving if you can't get back to it for longer.
Voila - cheap, low fat, comfort food. This is my nan's recipe and still reinds me of her. My kids love this too and I even did it without the bacon and mushed it for my son when he was a baby (DISCLAIMER: not sure they technically recommend giving liver to babies - was post 26 weeks though )