Ingredients

Serves 12

　　a trimmed 4- to 4 1/2-pound fillet of beef, tied, at room temperature

　　

For vinaigrette

3 heads garlic, unpeeled

　　2 teaspoons Dijon mustard

　　1/4 cup red-wine vinegar

　　1/4 cup balsamic vinegar

　　1 1/2 cups olive oil

　　6 cups arugula, washed thoroughly and spun dry

　　3 cups vine-ripened red cherry tomatoes, halved

　　3 cups vine-ripened yellow cherry tomatoes, halved

　　

Step 1

Preheat oven to 500°F.

　　

Step 2

Pat fillet dry and season with salt and pepper. In an oiled roasting pan roast fillet in middle of oven until a meat thermometer registers 130°F. for medium-rare meat, 20 to 25 minutes, and let cool to room temperature. Fillet may be roasted 2 days ahead and chilled, wrapped well.

　　

Make vinaigrette:

Step 3

Cut top 1/4 inch off each head garlic and wrap heads together in foil. Roast garlic 40 to 45 minutes, or until very soft, and let cool. Squeeze roasted garlic from each head (there should be about 1/3 cup) and in a blender or food processor blend together with mustard, vinegars, and salt and pepper to taste until smooth. With motor running add oil in a very thin stream and blend until emulsified. Vinaigrette may be made 4 days ahead and chilled in a tightly sealed jar. Shake vinaigrette well or reblend before serving.

　　

Step 4

Slice fillet thin. Arrange fillet, arugula, and tomatoes decoratively on a platter and serve with vinaigrette.