Gravy – over medium-high heat add 2 Tbsp olive oil and 2 Tbsp butter in large pan until bubbly, then add onion slices and mix well. Cover and cook over medium-low heat for 30 minutes, stirring often. Add sugar, mix well, cook for another 5 minutes or until onions are slightly carmelized. Remove pan from heat and stir in flour, then gradually stir in beef stock. Return pan to heat, bringing contents to a boil while stirring. Simmer for 3 – 5 minutes or until thickened. Season with salt and pepper.
While cooking the gravy, boil potatoes in salted water for about 20 minutes. Drain then mash the with remaining butter, cream, and mustard. Season with salt and pepper.
Broil or grill sausages during while cooking gravy and potatoes, for 15-20 minutes or until done. Turn often so they brown evenly.
Put potatoes on a plate, add sausages to one side, then add gravy. Goes great with an English ale such as Tetley’s or Boddington’s.