Heat the oil in a large skillet over medium-high heat. Add the sausages and cook, turning occasionally, until browned on all sides, about 8 minutes.
Remove the sausages from the skillet and place them on a baking sheet. Bake in preheated oven for 10 minutes.
Meanwhile, add the onions to the skillet and cook, stirring occasionally, until softened, about 5 minutes. Add the garlic, thyme, and oregano and cook, stirring, for another minute.
Add the beef stock, tomato paste, Worcestershire sauce, and Dijon mustard to the skillet and bring to a boil. Reduce the heat to low and simmer, stirring occasionally, for 10 minutes.
Meanwhile, place the potatoes in a pot and cover with cold water. Bring to a boil over high heat and cook until tender, about 15 minutes. Drain the potatoes and return them to the pot. Add the butter and mash until smooth.
Serve the sausages topped with the sauce and mashed potatoes.
Interesting Facts
Bangers and mash is a traditional British dish made with pork sausages and mashed potatoes.
The sausages are usually served with a flavorful onion and tomato-based sauce.
The dish is typically served with a side of vegetables or a green salad.
This dish is popular in pubs and restaurants throughout the UK.