San Francisco Deviled Crab

Ingredients

• 4 tablespoons butter
• 1 tablespoon oil
• 3/4 cup onion, finely chopped
• 1/2 cup celery, finely chopped
• 3 tablespoons flour
• 1 1/2 cups milk
• 1 cup light cream
• 1 1/2 teaspoons dry mustard
• 1/8 teaspoon Tabasco sauce
• 1 teaspoon Worcestershire sauce
• 1/4 cup dry sherry
• 2 tablespoons fresh lemon juice
• 2 tablespoons fresh parsley, chopped
• 3 eggs, hard-boiled and chopped
• 1 lb dungeness crabmeat, flaked
• salt
• pepper
• 1/2 cup parmesan cheese, grated