1

Put the celeriac in a pan of water and bring to the boil. Reduce the heat and simmer for 25-30 minutes until tender all the way through. Drain, then return the celeriac to the pan with the low-fat spread, season to taste and mash until smooth.

2

Meanwhile, heat the oil in a nonstick frying pan and add the steak. Cook for 1-2 minutes on each side until seared, but don’t cook it through – it should still be rare inside. Transfer to a plate and set aside.

3

Add the onion to the pan and cook for 6-8 minutes, until softened but not coloured. Add the garlic and paprika, and cook for 1-2 minutes until fragrant. Add the pepper and chestnut mushrooms and fry for 5-6 minutes until softened.

4

Add the beef stock, lemon juice and mustard, and simmer for 1 minute. Slice the steak into strips and add to the pan with all its juices, then simmer for 3 minutes until just cooked through.

5

Meanwhile, cook the green beans in a pan of boiling water for 4-5 minutes until just tender, then drain.

6

Stir the crème fraîche into the stroganoff and season to taste. Serve with the celeriac mash and green beans.