Peel and trim all the vegetables, cutting the root veg into 2.5cm dice. Cook the veg in a large pan of boiling salted water for 10 minutes, or until they are all cooked through. If you’re using swede or turnips, put them in about 5 minutes earlier than everything else as they take slightly longer to soften up. If using kale, just blanch this for a few minutes right at the end. Once all the veg is cooked, drain and leave to steam dry for a few minutes. Melt the butter and a lug of oil in a medium non-stick frying pan (roughly Put a medium non-stick frying pan (roughly 26cm–28cm) over a medium heat. Pick and chop the herb leaves, then add to the pan with the cooked vegetables. Season well with sea salt and white pepper, then mash everything up in the pan. Pat everything into a flat layer and cook for 3 to 4 minutes, or until a lovely golden crust starts forming underneath. Fold those crispy bits back into the mash, then pat and flatten down and repeat the process for about 15 or 20 minutes. Concentrate on building up flavours, character and crispiness. Halfway through the cooking, flip it over using a fish slice, or like a pancake if you’re brave. If it breaks don’t worry, just push it back together. Let it crisp up on the underside then nick a bit and taste it. This is the time to correct the seasoning. Once you’re happy, serve it with a blob of HP sauce and whatever else you fancy.