Wash your potatoes and, if you desire, peel them. Cut them into 1-inch cubes.
2 Lbs Potatoes
Add the potatoes to a pot and cover with an inch of water. Bring to a boil and then stir in 1-2 Tbsp of salt. Reduce the heat to medium and let the potatoes simmer for 10-15 minutes until fork tender.
Salt and Pepper to Taste
While the potatoes are boiling, heat a large skillet/pan over medium high heat. Cook the bangers/sausages in the pan. About 2-3 minutes on each side.
8 Bangers (Pork Sausage Links)
Once the bangers are cooked, remove them from the pan and add in the oil, onions and a heavy pinch of salt and pepper. Cook 15 minutes, stirring occasionally, until the onions are beginning to caramelize and have reduced to about half the volume.
2 Tbsp Oil, 2 Large Onions
When the potatoes are boiled, drain the water and return to the heat. Cook the drained potatoes another 1-2 minutes over medium-low heat to help get as much water out as possible.
If you are ricing the potatoes, do so now and add them back to the pot.
Add the milk, (optional) mustard powder, heavy pinches of salt and pepper, and all except 2 Tbsp of the butter to the potatoes. If mashing, mash them now. Cut the heat and taste for more salt and pepper.
1 C Milk, 2 tsp Mustard Powder, 2 Sticks Butter
Once the onions are cooked, add the flour and remaining 2 Tbsp of butter to their pan. Cook another 1-2 minutes, stirring to break up any clumps in the flour.
2 Tbsp All-Purpose Flour
Add the beer/wine, beef broth, and Worcestershire sauce and whisk constantly, being sure to scrape up the bits on the bottom of the pan, until the mixture thickens into an onion gravy. Let it return to a simmer.Note: The gravy will be relatively thin. You can thicken it further, if you prefer, by adding more flour. 2 Tbsp Worcestershire Sauce, 2 C Beef Broth, 1 C Guinness Beer or Red Wine
Add the bangers back to the onion gravy and cook another 4-5 minutes to let everything meld together. Give it one last taste for salt and pepper.
To serve, add a generous dollop of mashed potatoes to each plate and top with two bangers and as much gravy as you want. Green peas make a great vegetable pairing.