Prepare the Haggis: place the haggis in a large pan, cover with cold water and bring to a gentle simmer. Poach for 45–60 minutes (follow pack instructions if provided), turning occasionally. Keep warm when cooked.
Peel and chop the Floury Potatoes into even chunks so they cook evenly. Place in a pan of cold salted water, bring to the boil and simmer for 15–20 minutes until tender.
While the potatoes cook, peel and chop the Swede into similar-sized chunks. Put in a separate pan, cover with cold water and simmer for 20–25 minutes until soft.
Drain the potatoes and return to the pan off the heat. Add a generous knob of Unsalted Butter and a splash of Whole Milk, then mash until smooth and creamy. Season to taste with Salt and Black Pepper. Keep covered and warm.
Drain the swede and mash it with another knob of butter and a splash of Double Cream to achieve a silky texture. Season with a little extra Salt and Black Pepper to brighten the flavour.
When the haggis is cooked, carefully remove it from the water and either slice or pipe it onto a serving dish. If you like, you can brown slices briefly in a hot pan to add a crisp edge.
To serve, mound the mashed tatties on plates, add a good spoonful of neeps alongside, and top with slices or portions of the haggis. Finish with a small pat of butter or a drizzle of cream if desired and serve immediately.
