In a large skillet, heat 1 tablespoon of olive oil over medium heat. Toss in the sausages and cook until they are browned on all sides and cooked through, about 15-20 minutes.

While your sausages are sizzling, bring a pot of salted water to a boil. Add the chopped potatoes and cook until tender, about 15 minutes. Drain the potatoes and return them to the pot. Add the milk, butter, salt, and pepper, then mash until creamy and smooth.

In the same skillet you used for the sausages, add the remaining tablespoon of oil and sauté the onions over medium heat until they're caramelized and golden brown, about 10 minutes. Stir in the broth, Worcestershire sauce, and let it simmer for about 5 minutes. If you like your gravy a bit thicker, mix the cornstarch with water and add it to the gravy while stirring.

Spoon a generous portion of mashed potatoes onto each plate, nestle your fabulous sausages on top, and drizzle that delicious onion gravy all over the masterpiece. Sprinkle with fresh parsley if desired.