Bring a pot of salted water to a boil. Add potatoes and cook until tender but still firm, about 15 minutes
Drain in a small saucepan heat butter and milk over low heat until butter is melted.
Using a potato masher or electric beater, slowly blend milk mixture into potatoes until smooth and creamy. Season with salt and pepper to taste.
Onion Gravy
Melt the butter in a saucepan over medium high heat. Add the sliced onions and cook for about 30 minutes until caramelized (deep golden), if you want a classic dark gravy, you can add a tablespoon or two of sugar or coconut sugar to the onions to caramelize it to a darker shade.
Add the red wine and thyme, bring to a rapid boil for 2 minutes, reduce the heat and simmer for 10 minutes.
Add the bone broth, mustard, salt, pepper and Worcestershire sauce, bring to a boil, reduce the heat to a low simmer and simmer, uncovered, for 20 minutes
Add the vinegar, and season with additional salt and pepper.
While the gravy is simmering, grill or sear in a saucepan:2 lb Belcampo Tuscan Sausages
Assemble plates with:Mashed potatoes topped with 2 grilled sausages and buried in Onion Gravy.