Preheat the oven to 190°C fan
Add sprouts to a 9 inch baking tray, dress in olive oil and season
Roast sprouts for 5 minutes
Set a large saucepan to medium-high heat and add butter to melt
Add garlic and soften for 2 minutes
Add cream, thyme, nutmeg, vegetable stock and cheese to the pan
Stir together and warm for 30 seconds
Season the sauce to taste
Pour sauce over the sprouts and bake for 10 minutes
In a bowl, mix together pecans, pumpkin seeds, cayenne pepper, maple syrup, salt and olive oil
Sprinkle topping over the gratin
Roast for another 6 minutes until crisped up
Serve straight away
