Bring a large pan of water to the boil. Add the sprouts, cover and bring back to the boil. Cook for 5 minutes, until almost al dente. Drain well.
Melt the butter in a wide frying pan over a medium heat. Add the garlic and nuts and cook, stirring for 2 minutes until the nuts are lightly toasted. Add the sprouts, sage and some seasoning and cook, stirring for a further 2-3 minutes or until the sprouts are al dente. Serve.