1. Trim the Brussels and peel away any tatty outer leaves, halving any larger ones and keeping the smaller ones whole. Cook in a large pan of boiling salted water for 5 minutes, then drain and leave to steam dry.
2. Melt the butter in a large frying pan on a medium-low heat. Pick and add half the sage leaves, cook for 3 minutes, or until crispy, then tip into a small bowl.
3. Place the pan back on the heat and squeeze the sausage meat from the skins directly into the pan, breaking it up with the back of a spoon. Cook for 3 to 5 minutes, until golden and crispy, while you peel and finely slice the onion, and pick and finely chop the remaining sage.
4. Add the onion and chopped sage to the pan and cook for 5 minutes on a medium-high heat, or until the onions have softened, stirring occasionally.
5. Peel and core the apple, then finely dice. Tip into the pan, and add the sprouts too, then add the Worcestershire sauce and toss until hot through.
6. Transfer to a serving platter, scatter over the crispy sage leaves, and dig in!
Tip: For a veggie-friendly version, swap the sausages for chopped chestnuts, and use anchovy-free Worcestershire sauce.