Shepherd’s Pie

Dice the onion, carrot and celery. In a heavy based frying pan over high heat, stir fry them until soft, for about 4min. Add the meat and garlic, stir for 4 more min until brown. Pour the wine and let it reduce almost completely. Add the Worcestershire sauce, tomato puree, the herbs tied with a string, the stock and bring it to a boil. Reduce heat and simmer until the thickened. Season well with salt and pepper.;Boil the potatoes, skin on, until you can easily stick a knife through it. Strain, peel and mash it with butter. Stir in the egg yolks and season with salt and pepper.;Pull out the tied herbs and spoon the meat into the bottom of an ovenproof dish. Layer the mash all over it and form peaks with a fork. Sprinkle it with the parmesan cheese and bake in a 180C/350F oven for about 20min, until golden.