1. Make marinade: Combine all ingredients in bowl and whisk until smooth.

2. Place beef in shallow nonaluminum dish. Add marinade; toss to coat. Cover and refrigerate 2 hours or overnight.

3. Combine mayonnaise and tarragon in cup; set aside. Thirty minutes before serving, prepare grill or heat broiler. Remove beef from refrigerator. Arrange onion slices in single layer in shallow microwaveproof dish and sprinkle with water. Cover and microwave on High 2 minutes. Let stand 2 minutes. Drain onions. Brush both sides with oil and sprinkle with salt and pepper. Grill in a vegetable basket or broil 3 inches from heat source 3 minutes per side, until lightly charred; keep warm.

4. Grill beef 3 inches from heat source 4 to 5 minutes per side for medium-rare. Cover and let stand 10 minutes. Meanwhile, grill bread, cut side down, about 1 minute, until golden. Brush each side with tarragon mayonnaise.

5. Slice beef thin diagonally. Layer arugula on bottom bread slice. Top with even layers of sliced beef, then grilled onions and remaining bread. Cut crosswise into 6 sandwiches. Makes 6 servings.

A case of hero worship! Grilled sweet onion and a tarragon mayonnaise give this hearty sandwich terrific flavor.

of difficulty: Easy Microwave

Per Serving Calories 480 Total Fat 23 g Saturated Fat 5.5 g Cholesterol 45 mg Sodium 747 mg Carbohydrates 43 g Protein 22 g Calcium 91 mg Fiber 3 g

MasterCook formatted by Joyce M. Bennis (Joyce_B@msn. Com)