Sausage and Mash

Preheat your oven to 400°F (200°C). Place the sausages on a baking sheet and cook for 25-30 minutes, turning halfway through, until browned and cooked through.
Meanwhile, place the potatoes in a large pot and cover with cold water. Add a pinch of salt and bring to a boil. Cook until tender, about 15-20 minutes. Drain well.
In the same pot, mash the  potatoes with milk, butter, salt, and pepper until smooth and creamy. Keep warm.
To make the onion gravy, heat the olive oil and butter in a large skillet over medium heat. Add the onions and cook, stirring often, until they are caramelized and golden brown, about 15-20 minutes.
Sprinkle the flour over the onions and cook, stirring constantly, for 1-2 minutes.
Gradually add the  beef broth, stirring constantly to prevent lumps. Add the Worcestershire sauce, and season with salt and pepper to taste. Simmer for 5-10 minutes, until the gravy has thickened.