Brussels Sprouts and Roasted Red Onions

Preparation

1. Step 1

   Preheat oven to 425° F.

   Step 2

   Trim onions, keeping root ends intact, and cut each lengthwise into 6 wedges, keeping wedges intact. In a large bowl toss onions with oil and salt and pepper to taste. In 2 shallow baking pans arrange onions in one layer and roast in upper and lower thirds of oven 20 minutes. Carefully turn onions over and switch position of pans. Roast onions 20 minutes more, or until just tender and some edges are golden brown.

   Step 3

   Trim Brussels sprouts and have ready a large bowl of ice and cold water. In a large saucepan of boiling salted water cook sprouts until just tender, 8 to 10 minutes, and drain in colander. Transfer sprouts to ice water to stop cooking and drain in colander. Vegetables may be prepared up to this point 1 day ahead and chilled separately, covered.

   Step 4

   In a small bowl stir together mustard and water. In a 12-inch heavy skillet cook onions and sprouts in butter over moderately high heat, stirring, until heated through and stir in mustard mixture and salt and pepper to taste.