In a bowl, combine 2 teaspoons of salt with water. Place the lamb's liver in the salty water, then refrigerate it for 2 hours.
While the liver is soaking, remove the bacon rind and dice it into large pieces. Slice the onion.
After 2 hours, take the liver out of the water, allowing it to drain or pat it dry. Remove the skin from both sides by gently sliding a knife underneath and peeling it away.
Cut the liver into thin, bite-sized pieces, ensuring you trim away any sinew.
On a plate, place 2 tablespoons of flour and season it generously with salt and pepper. Coat the liver pieces in the seasoned flour, making sure they are well covered, then transfer them to another plate.
Heat a frying pan over medium heat, add a small amount of oil, and sauté the sliced onion until it begins to brown and soften, which usually takes a few minutes.
Introduce the diced bacon and continue cooking for an additional 3 minutes or until the bacon is thoroughly cooked. Remove this mixture from the pan.
Increase the heat to medium-high, add more oil to the pan, and place the floured liver pieces into it, leaving some space between them. Fry and turn the liver for about five minutes until it's nicely browned on all sides, then remove it from the pan. Reduce the heat to medium.
If needed, add a bit more oil to the pan and the remaining flour. Stir continuously for 1 minute. Don't worry about the brown, crispy bits at the bottom of the pan; they add flavor.
Pour in the stock and stir well to create a gravy. Make sure to scrape up all the crispy bits from the pan, as they'll enhance the flavor.
Simmer the gravy for a few minutes until it slightly thickens. Then, reintroduce the bacon and liver into the stock. Cook for an additional 5-10 minutes or until the liver is fully cooked through.
Serve on a bed of mash potatoes with roast carrots and peas.
