- Preheat oven to 350 degrees.
- Combine chestnut purée and heavy cream in a medium-size pot and bring to medium-high heat and reduce by half. Season puree with salt and pepper to taste.
- Place a medium saucepan on high and add one tablespoon of canola oil. Once hot, add heirloom pumpkin, squash, parsnips and Yukon gold potatoes. Turn heat to low and cook until a fork can easily pierce the vegetables, approximately 3−5 minutes.
- Remove from heat and add rosemary, nutmeg, allspice, and 1 tablespoon of unsalted butter. Season vegetables with salt and pepper to taste and set aside in a warm area.
- In a medium saucepan heat the remaining one tablespoon of canola oil on high heat. Season scallops with salt and white pepper. Once the oil has almost reached a smoking point, place the scallops in the pan with the flat side down. Sear until golden brown on one side and turn scallops over. Add the remaining 1 tablespoon of unsalted butter to the pan and place scallops in the oven for 3−4 minutes.
- Divide the winter vegetable mix among the four plates.
- Place one seared scallop on top of vegetable mix and drizzle with one tablespoon of chestnut purée-cream mixture per plate.