Directions

1. Melt 2 tablespoons butter in a saucepan over medium high heat. Add the sliced onions and sugar and cook for about 30 minutes until caramelized (deep golden).
   
2. Add the red wine, thyme, and rosemary, bring to a rapid boil for 2 minutes, reduce the heat and simmer for 10 minutes. Add the broth, mustard, 1/2 teaspoon salt, 1/8 teaspoon pepper and Worcestershire sauce, bring to a boil, reduce the heat to a low simmer and simmer, covered, for 20 minutes. Remove sprigs of herbs.
   
3. In a small bowl add cornstarch and water then mix well. Add cornstarch mixture to pot then add the vinegar, simmer another minute or two until thickened, whisking continuously. Add 1 tablespoon cold butter and whisk until dissolved. Sprinkle with parsley and stir well. Set pot aside and keep warm.
   
4. Preheat the oven to 400 degrees F. Place the potatoes in a pot of water and add 1/4 teaspoon salt. Bring to a boil, lower the heat to a steady simmer and cook for about 15-20 minutes or until potatoes are just tender when pierced with a knife.
   
5. Thoroughly drain the potatoes and place them back in the empty pot set over very low heat just to maintain warmth. Mash the potatoes until fluffy and you've reached the desired degree of smoothness. Stir in 2 tablespoons butter. Once melted stir in the hot milk gradually, allowing time for the potatoes to absorb the liquid after each addition. Season with salt and pepper to taste.
   
6. While the potatoes are boiling place the sausages in a baking dish with a little oil and roast the sausages for about 10 minutes on each side or until nicely browned.
   
7. To serve, place a mound of mashed potatoes on each plate, lay the sausages on the mashed potatoes and top with onion gravy. Peas are a traditional side.