Marinated Flank Steak

Ingredients

• 2 1/2 lb. round or flank steak
• 1/2 c. chopped onion
• 1/2 c. lemon juice
• 1/4 c. salad oil
• 1/2 tsp. salt
• 1/2 tsp. celery salt
• 1/2 tsp. pepper
• 1/2 tsp. thyme
• 1/2 tsp. oregano
• 1/2 tsp. rosemary
• 1 c. sherry