- Preheat your oven to 425°F. 
- Trim the Brussels sprouts by cutting off the ends and removing any damaged outer leaves. 
- Wash and dry the Brussels sprouts thoroughly. 
- Place the sprouts on a baking tray. Drizzle with olive oil and sprinkle with sea salt and black pepper. 
- Mix the Brussels sprouts so they are evenly coated in oil and seasoning. 
- Roast the Brussels sprouts in the oven for 25 minutes, or until they are golden and crispy. 
- While the sprouts roast, melt the butter in a frying pan over medium heat and add the chopped garlic and sage. 
- After 2 minutes, add the cream to the pan and reduce the heat to low. Simmer until the mixture thickens slightly. 
- Remove the sprouts from the oven and transfer them to a casserole dish. Pour the creamy garlic mixture over the top. 
- Sprinkle the grated cheese and breadcrumbs evenly over the sprouts. 
- Return the dish to the oven and bake for an additional 10 minutes until the top is golden and bubbly. 
- Let the dish cool a bit before serving.