1. Preheat the oven to 200°C (400°F).

2. In a large saucepan, combine the cauliflower florets, a pinch of salt, and enough water to cover. Bring to a boil over high heat, then reduce the heat to low, cover, and simmer until the cauliflower is very tender, about 10-12 minutes. Drain well.

3. Transfer the cooked cauliflower to a blender or food processor. Add 60g (1/4 cup) of the butter and process until smooth and creamy. Season with salt and white pepper to taste. Keep warm.

4. Pat the cod fillets dry with paper towels and season both sides with salt and white pepper.

5. Heat the vegetable oil in a large ovenproof skillet over medium-high heat. Add the cod fillets, skin-side down, and sear until the skin is crispy and golden brown, about 3-4 minutes. Carefully flip the fillets and transfer the skillet to the preheated oven. Roast until the fish is cooked through and easily flakes with a fork, about 6-8 minutes.

6. While the cod is in the oven, prepare the red wine reduction. In a small saucepan, combine the red wine, sugar, red wine vinegar, and thyme sprigs. Bring to a boil over high heat, then reduce the heat to medium-low and simmer until the sauce has reduced by about half and thickened slightly, about 10-12 minutes. Remove and discard the thyme sprigs.

7. To serve, spoon the cauliflower purée onto serving plates. Place a cod fillet on top of each portion of purée, skin-side up. Drizzle the red wine reduction around the fish and purée, then garnish with the capers. Serve immediately, and enjoy your exquisite restaurant-quality meal!

8. Safety tip: Be cautious when handling the hot skillet and flipping the fish to avoid oil splatters.