The Hirshon British Bangers and Mash with Onion Gravy

Ingredients

• onion gravy
• 2 tablespoons grapeseed oil
• 2 tablespoons butter TFD prefers Kerry Irish butter in this recipe
• 2 onions medium, peeled and thinly sliced
• 4 teaspoons onion
• jam
• 1 1/4 pints homemade beef stock rich
• 2 teaspoons fresh thyme leaves
• 4 teaspoons cornstarch
• 1 tablespoon guinness
• beer
• Maldon sea salt to taste
• freshly ground black pepper to taste
• demiglace to taste
• 2 pounds Yukon Gold potatoes peeled and quartered
• 6 tablespoons whole milk preferably from a Jersey cow
• 1 stick butter cubed - TFD likes Kerry Irish butter if you can find it
• salt to taste
• freshly ground black pepper to taste
• 2 tablespoons grapeseed oil
• 8 Banger sausages Banger
• 1/4 cup hard cider Somerset, if you can find it, or TFD's preferred substitute