Trim off the stems and remove any limp leaves from Brussels sprouts
Blanch the sprouts in boiling water to cover for 5 minutes
Drain and rinse under cold water to stop the cooking Heat a large frying pan and add the olive oil garlic and onion Saute a few minutes until the onion just becomes tender
Add the blanched drained Brussels sprouts
Saute a few minutes until the Brussels sprouts are cooked to your liking
Add the vinegar and toss so that all the sprouts are coated with vinegar
Add the butter and salt and pepper to taste and toss together again Serves 6 to 8