The Christmas feast stands or falls on its roast potatoes. If the turkey is a bit dry, you can slosh extra gravy on, and soggy sprouts are the sort of thing generations bond over. But potatoes that are anything other than cracklingly crisp, hot and golden, are a dinner disaster. Ashley Palmer-Watts well understands the power of the roastie. The chef worked for 20 years under Heston Blumenthal, launched his two-Michelin-star restaurant Dinner, in London, in 2011, and oversaw the kitchen at Blumenthalâs Michelin-starred Hindâs Head in Bray. But Sundays are spent cooking lunch (nine times out of 10 a roast chicken), for his wife, Emma, and children, Max and Sophia â and Palmer-Watts will be at the stove on Christmas Day as well.