A simple but very flavorful main course that can be served with equal ease for a sit-down or buffet dinner.

• 1 2- to 2 1/4-pound top sirloin or Porterhouse steak, about 1 1/4 inches thick

• 1/4 cup olive oil

• 1/4 cup fresh lemon juice

• 6 large garlic cloves

• 2 tablespoons Dijon mustard

• 1 tablespoon chopped fresh rosemary

• 2 teaspoons grated lemon peel

Place steak in heavy large re-sealable plastic bag. Puree remaining ingredients in blender or processor. Season marinade with salt and pepper. Pour marinade into bag with steak; seal bag. Let steak marinate at room temperature 2 hours or chill up to 6 hours, turning bag occasionally.

Preheat broiler or prepare barbecue (medium-high heat). Broil or grill steak until cooked to desired doneness, about 7 minutes per side for medium-rare. Transfer steak to platter; let stand 15 minutes. Thinly slice steak crosswise.

Makes 6 servings.