Sprimp Spaghetti

1 1/2 cups butter
1 cup chopped onion
1 tablespoon dried parsley flakes
1 tablespoon Worcestershire sauce
1 teaspoon salt
1 teaspoon ground black pepper
1/2 teaspoon dried basil
1/2 teaspoon dried thyme
1/4 teaspoon garlic powder
3 pounds medium fresh shrimp, peeled and deveined
1 (12-ounce) package thin spaghetti, cooked and drained
1 (8-ounce) package processed cheese, cut into 1/2-inch pieces

Preheat oven to 350.
In a large skillet, melt butter over medium-high heat. Add onion; cook for 5 minutes or until tender. Stir in parsley, Worcestershire sauce, salt, pepper, basil, thyme, and garlic powder. Pour mixture into a 13x9-inch baking dish; add shrimp, tossing gently to coat. Bake for 25 minutes, stirring occasionally.
Remove from oven; stir in spaghetti and cheese. Return to oven, and bake 5 minutes, or until cheese is melted, stirring to combine.