Roast Beef Fillet with Creamy Celeriac-and-Horseradish-Cream Salad

I do love celeriac, and this combination of slivers of snappy celeriac tossed in a mixture of yoghurt, cream and horseradish, and served over rosy slices of roast beef, is just my idea of heaven.

For this recipe I used fresh, grated horseradish steeped in olive oil (recipe here) but you could use creamed horseradish. How much you add is up to you, but the horseradish shouldn't overpower the delicate taste of the celeriac and its creamy dressing.

This is also lovely with pork fillet: try adding a grated apple to the mixture.

Roast Beef Fillet with Creamy Celeriac and Horseradish Salad

For the fillet:
1 large fillet of beef
a little olive oil and butter
3 t Dijon mustard
black pepper

For the salad:
2 young celeriac, each about the size of an orange
1/2 cup (125 ml) thick plain yoghurt
1/2 cup (125 ml) pouring cream
1 T (15 ml) creamed horseradish, or freshly grated horseradish, to taste
a squeeze of fresh lemon juice
a pinch of salt
white pepper
alfalfa spouts to top (optional)

First roast the fillet. Preheat the oven to 190°C, and place a metal roasting pan in the oven.

Put a fat dollop of mustard in the palm of your hand and smooth it all over the fillet. Sprinkle with olive oil and grind over plenty of fresh black pepper. Heat a little olive oil and butter in a large frying pan over a high flame. The fat should be very hot, but not actually smoking. Brown the fillet on all sides; this shouldn't take longer than six or seven minutes.

Now put the fillet onto the heated roasting pan and bake in the pre-heated oven for 10-20 minutes, depending on the degree of pinkness you want. (A slim fillet takes about 10 minutes; a full-size one 15-20. If you're not sure, cut a deep slit in the thickest part of the fillet to check for doneness). You'll find more detailed instructions for cooking fillet here.

Now make the salad. Peel the celeriac with a sharp knife and cut into very thin slices (you could use a mandolin). Stack the slices vertically, and cut them into strips or matchsticks. Place in a bowl. In another bowl, whisk together the yoghurt and cream, and add enough horseradish to give the dressing a nice bite. Add a good squeeze of lemon juice and season with salt and pepper. Pour just enough dressing over the celeriac strips to light coat each piece: the salad should not be swimming in dressing.

Remove the fillet from the oven, wrap in tin foil (or in cling-film) and set aside to rest for 5 minutes.

Unwrap the fillet, carve into slices. Arrange the slices on a big platter, pile the celeriac in the middle, and top with tangle of crunchy alfalfa sprouts.

Serves 8-10 as a starter; 6 as a main course.