Step 1

Place the Brussels sprouts in the feed tube of the food processor fitted with a large slicing disc. (There is no need to core them.) Process the Brussels sprouts until they're all sliced.

Step 2

Place the butter and olive oil in a large (12-inch) saute pan and heat it over medium heat. Add the sliced Brussels sprouts, 1 1/2 teaspoons salt, and 1/2 teaspoon pepper and saute them, stirring frequently, for about 4 to 5 minutes, until tender but still bright green. Stir in the balsamic vinegar, season to taste, and serve hot.