Toss the olive oil, Brussels sprouts, Chopped Garlic in Oil and Fennel Seeds together, transfer to a baking tray and roast in the oven for 20 minutes.
Remove from the oven and add the apple, walnut pieces and Sage. Toss to gently coat all the ingredients and pop back in the oven for a further 10 minutes, or until the apples and Brussels sprouts are tender.