Heat half of the oil in a frying pan and fry the chicken on both sides until brown.
Pour the whiskey into a saucepan and add the oregano. Cook until reduced by half. Add the marmalade and stir until fully incorporated.
Brush the chicken breasts with the mixture and bake for 20 minutes.
While the chicken is in the oven, prepare the carrot mash.
Boil the carrots for 5 minutes, drain, toss in olive oil and scatter over a roasting sheet.
Add the garlic and roast alongside the chicken for 10 minutes.
Cook the potatoes for about 15 minutes, until soft.
Drain and add the roasted carrot and garlic; mash until soft. Stir the cream and butter into the mash and season to taste.
Take the chicken out of the oven and remove from the roasting tin - leave to rest for 5 minutes. Pour the white wine into the tin and place over a low heat, scraping and lifting any meat sediment from the tin. Cook down for a few seconds to make a jus.
To serve, place a dollop of mash in the centre of each plate, slice the chicken breasts and arrange on the top. Drizzle over the jus, and serve immediately.