The day before, preheat the oven to 200C/400F. Wash, peel and cube up the pumpkin.
Toss pumpkin with olive oil, salt and pepper on a baking sheet lined with foil and parchment paper. Roast for 30-45 minutes, or until tender.
Meanwhile, salt and pepper the steaks on both sides. Set on a wire rack over a dish, and leave in the fridge uncovered overnight.
Once pumpkin is tender, allow to cool before puréing. Work in batches if necessary. Mix in Parmesan, adjust for seasoning, and refrigerate overnight.
On the day, whisk the salad dressing ingredients together in a mixing bowl. Wash and dress the salad.
Plate the pumpkin purée, and microwave to reheat.
Sear the steaks on both sides in a well-preheated cast iron pan. Plate up and serve hot.