For the mash: Preheat the oven to 350 degrees F. Toss the cauliflower with the olive oil, salt, turmeric and curry powder. On a baking sheet lined with parchment paper, roast the cauliflower for 20 minutes.
While the cauliflower roasts, boil the potatoes until fork tender, 15 minutes, and then strain. Melt the butter and cream in small saucepan. In a food processor (or large bowl and immersion blender) process the still-warm cauliflower and potatoes, slowly adding the cream and butter until you reach your desired consistency. Fold in the cheese, and then season with salt and pepper.
For the gravy: Heat a large pan over low heat. Add the olive oil and sweat the onions for 20 minutes. Add the butter and cook for 2 minutes, then add the flour, and cook for 1 minute. Pour in the chicken stock and cook for 10 minutes, then add in the cream and vinegar. Season with salt and pepper. Adjust the thickness of the gravy with more stock as needed.
For the sausages: Rinse and treat the casings according to package instructions. Mix the pork, parsley, curry powder, shallots, wine, salt and chile flakes by hand in bowl. Using a sausage stuffer, stuff the mixture into the casings. Make each link 6-inches long, 16 links total. Cook the sausages on a grill or cast-iron pan set over medium-low heat for 10 minutes. If they're cooked over higher heat, they may split open.
Serve on a large dinner plate. Place a scoop of cauliflower mash and ladle a small amount of onion gravy (about 1/4 cup) on top. Place 2 sausages on top of the gravy and cauliflower mash, and finish with a tablespoon of mint chutney.