1. Preheat your oven to 400°F or 200°C.

2. In a large bowl, combine 250g or 8.8oz grated potato, 1 egg, 60g or 2.1oz all-purpose flour, a pinch of salt, and a few grinds of pepper. Mix everything together until well combined.

3. Divide the mixture into 4 equal portions and shape each one into a round cake.

4. Place the cakes on a baking sheet lined with parchment paper.

5. Roast a 400g or 14.1oz beef filet in the oven for about 45 minutes, or until it reaches your desired level of doneness.

6. While the beef is roasting, melt 30g or 1.1oz butter in a large skillet over medium heat.

7. Add 2 sprigs of fresh thyme to the skillet and cook for 1 minute, stirring occasionally.

8. Add 120g or 4.3oz cherry tomatoes to the skillet and cook for 2-3 minutes, or until they start to soften.

9. Add 1 sprig of fresh rosemary, 1 tsp or 5g mustard seeds, 1 tsp or 5g granulated sugar, 2 tbsp or 30g red wine vinegar, a pinch of salt, and a few grinds of pepper to the skillet. Stir everything together.

10. Remove the beef from the oven and let it rest for 5 minutes before slicing it thinly against the grain.

11. Serve the sliced beef with a potato cake and spoon the red wine sauce over the top.