Grilled Tenderloin of Beef with Spicy Fresh Herb Vinaigrette

To make vinaigrette: In a blender or the bowl of a food processor fitted with knife blade, combine herbs, red pepper flakes, and garlic. Pulse until well chopped. Add vinegar and pulse to combine. With the motor running, slowly add 2/3 cup olive oil until vinaigrette is almost pureed. Add salt and adjust seasoning to taste. Transfer to a serving bowl and set aside. To make beef: Preheat gas grill to medium-high, or prepare a charcoal grill for direct grilling over medium-high heat. Brush meat with olive oil and sprinkle with salt and pepper. Place on grill, cover and cook 30 to 40 minutes, turning every 5 minutes. For rare beef, remove from grill when a meat thermometer reads 115 degrees (120 degrees for medium rare). Let sit 20 minutes; the temperature of the tenderloin will rise about 10 degrees and it will continue to cook. Slice and serve warm or at room temperature, topped with herb vinaigrette.