This salad is a great way to bring new life to leftover beef. If you don't have any leftovers, you can also buy sliced roast beef from the deli to make this good-looking, easy-to-assemble salad. Use yellow and red tomatoes for the best visual effect. Be casual about the quantities of garnishes--use more of what you like.

2 teaspoons Dijon mustard

2 tablespoons red wine vinegar

1/2 cup olive oil

1 teaspoon capers, chopped

3 tablespoons finely chopped parsley

Salt and freshly ground pepper

4 cups arugula leaves

8 ounces (250 grams) steak, thinly sliced

1 cup chopped cornichons or pickles

2 cups sweet or red onion, chopped

2 cups chopped tomatoes

1/2 cup chopped black olives

Whisk together mustard and vinegar in a medium bowl. Slowly whisk in olive oil until mixture thickens. Stir in capers and parsley and season with salt and pepper to taste.

Place arugula on a platter. Layer half of the meat, pickles, onion and tomatoes and pour over half the vinaigrette. Repeat the layers and pour over remaining vinaigrette. Garnish with olives and scatter with extra arugula. Serves 4 to 6.