2) Heat the oil in a pan and sear the fillets on both sides to the required doneness.
3) Boil 2 whole pearl onions till soft, peel and slice in half and sear in a pan with butter.
4) Spread the parsnip puree on each plate and place the fillet, pearl onions and a slice of the pommes Anna. Pour the sauce gently over and serve.
For the parsnip puree:
1) In a pan, boil the parsnip and onion until soft.
2) Blend to a puree in a blender, adding some of the cooking water if necessary to achieve the right consistency.
For the pommes Anna:
1) Preheat the oven to 200C/Gas 6. Peel and slice the potatoes on a mandolin. Rinse under cold water and pat dry.
2) Arrange the potato slices in a shallow ovenproof dish in overlapping circles, brushing butter and seasoning over each layer. Cover with a lid and bake for 45 minutes or up to an hour.
For the sauce forestiere:
1) Saute the bacon in a hot pan until it begins to release its fat. Add the onion mushrooms and saute in the bacon fat.
2) Add the jus and reduce till you get the desired consistency.