Rinse the stomach thoroughly and soak overnight in cold, salted water. Squeeze out as much air as possible. Rinse the organs. In a large pot of boiling, salted water, cook on medium heat for 2 hours. Save about 2 cups of the liquid. Remove any gristle or skin and discard. Mince all the organs except the liver – that is to be grated. In a large bowl, combine the meat, suet, onions and toasted oats. Season with salt, pepper and dried herbs. Moisten with some of the cooking water so the mixture binds. It should bind together lightly, but still able to be crumbled. Remove the stomach from the water and drain well. Fill approximately 2/3 with the mixture. Sew or tie the stomach closed, like you would a pudding bag. Be sure to leave room for expansion, so tie about 4-5” above the meat mixture. Use a turning fork to pierce the stomach several times. This will prevent the haggis from bursting. In a large pot of boiling water, gently place the filled stomach. Cook over medium-high heat for 2.5-3 hours, turning as necessary. Serve with potatoes and mashed turnip.