Heat the oven to 200C/180C fan/gas 6. Heat the oil in a medium-sized ovenproof frying or skillet pan. Add the potatoes and fry over a medium-high heat for 15 mins or until golden brown and crisp. Season to taste.

Nestle bundles of the pastrami into the pan, sprinkle over the emmental, then make two indentations in the potatoes and gently crack the eggs into each one. Transfer the pan to the oven and cook for 8-10 mins or until the egg whites have just set with the yolk still runny. Season the eggs with pepper, then top the hash with the gherkins. Finish with a squirt of mustard, if you like.