One benefit of the cold weather, is the lengthening of the growing time of root vegetables. The slower the growth, the more time the root spends underground, soaking up all the nutritional goodness from the earth. This effectively makes winter root-vegetables more nutritionally powerful than in warmer times of the year.
It also makes them tastier, with the frosty temperatures acting to convert some of the starch in veggies like Parsnips, Carrots and Celeriac into sugars, giving them a nicely sweet flavour.
Winter is a perfect time to just toss a mix of root vegetables in olive oil, salt and pepper and roast them in a hot oven. Or get more creative and coat dutch-carrots in ground cumin and serve with labna and pomegranate molasses.
Also try replacing the humble potato mash with either celeriac or parsnip puree. Simmer each in butter, milk and a little garlic until soft, then puree using a stick blender. Beautiful