Preheat the oven to 375°F (190°C).

Cut the cauliflower into thick slices, about 1-inch (2.5 cm) thick.

Brush both sides of the cauliflower slices with olive oil and season with salt, black pepper, smoked paprika, and garlic powder.

Heat a large oven-safe skillet over medium-high heat and add a drizzle of olive oil.

Place the cauliflower slices in the skillet and sear on both sides until golden brown, about 2-3 minutes per side.

Transfer the skillet to the preheated oven and roast the cauliflower for 15-20 minutes, or until tender and slightly caramelized.

In a small saucepan, heat the vegetable stock and butter over medium heat until the butter is melted.

Remove the skillet from the oven and pour the vegetable stock mixture over the cauliflower slices.

Add fresh thyme sprigs to the skillet.

Return the skillet to the oven and continue roasting for another 5 minutes to allow the flavors to meld together.

Remove the skillet from the oven and squeeze fresh lemon juice over the cauliflower slices before serving.