-
1
Preheat oven to 500F.
-
2
Pat fillet dry and season with salt and pepper.
-
3
In an oiled roasting pan roast fillet in middle of oven until a meat thermometer registers 130F.
-
4
for medium-rare meat, 20 to 25 minutes, and let cool to room temperature.
-
5
Fillet may be roasted 2 days ahead and chilled, wrapped well.
-
6
Cut top 1/4 inch off each head garlic and wrap heads together in foil.
-
7
Roast garlic 40 to 45 minutes, or until very soft, and let cool.
-
8
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.
-
9
With motor running add oil in a very thin stream and blend until emulsified.
-
10
Vinaigrette may be made 4 days ahead and chilled in a tightly sealed jar.
-
11
Shake vinaigrette well or reblend before serving.
-
12
Slice fillet thin.
-
13
Arrange fillet, arugula, and tomatoes decoratively on a platter and serve with vinaigrette.
