• Par-boil the sausages in Guinness beer and beef broth for 10 minutes. Turn off heat and keep sausages in beer broth mixture covered until ready to be roasted.

Prepare Red Onion Gravy

• In a large fry-pan heat butter and oil together over medium heat. Add the sliced onions and saute until soft and slightly translucent. Add the garlic and season with the brown sugar and salt. Lower the heat to it lowest setting and continue to saute until onions have caramelized to a deep golden brown color (approx. 30 minutes).
• Add red wine and fresh thyme allow to reduce by half until the wine coats a spoon (approx. 15 minutes). Mix in the dijon mustard, Worchestershire sauce, balsamic vinegar, and beef broth. Turn heat up to medium and bring to a simmer. Add the cornstarch slurry, mix throughly until thickened. Whisk in the cold butter a little at a time until completely incorporated and glossy. Set aside and keep warm

Mashed Potatoes

• Add cut potatoes into a large pot, cover potatoes with cold water and season with salt. Bring the pot to a boil over medium heat, until fork tender approxiamately 25 mins, once boiling. In the meantime melt the butter and heat the milk. On a side note, this is a good time to preheat the oven to 425° F
• Drain potatoes well. Run potatoes through a food mill or ricer back into the pot. Alternatively, return drained potatoes back into the pot and manually begin to mash. Add the melted butter and incorporate well before adding the warm milk. continue mashing and stirring until a creamy texture is achieved. Season with salt and pepper.

Finishing the Sausages and Plating

• Remove the sausages from the beer broth and place them in to a large baking pan, leaving room between the sausages, Coat suasges with the oil and bake 10 - 15 minutes until skin is browned and crisp. Flip sausages half-way in between.
• Once saussges are done, Plate the mash first, with some gravy pored on top, Place two sausage on top of the potatoes per plate and top with more gravy.