Crab Bisque Macaroni and Cheese

I found this on the Wisconsin Dairy Board. I'm on a low carb diet so this is a no-no for now. I know just what I'm having when I go on my next planned "cheat." Someone make this quick so I can live vicariously through your review!

• Ready In: 40 mins
• Serves: 10

Ingredients

• 1 (16 ounce) package penne pasta, cooked,drained
• 4  tablespoons butter, divided
• 1  medium onion, chopped
• 3  tablespoons flour
• 1  cup milk
• 1 (14 1/2ounce) can chicken broth
• 1 (14 1/2ounce) can diced tomatoes, drained
• 1 1⁄2 teaspoons fresh rosemary, minced or 1⁄2 teaspoon dried rosemary
• 1⁄2 teaspoon salt
• 1⁄4 teaspoon pepper
• 2  cups cheddar cheese, shredded,divided (8 ounces)
• 2  cups monterey jack cheese, shredded,divided (8 ounces)
• 1 (16 ounce) can lump crabmeat, drained
• 1⁄4 cup sherry wine

Directions

1. Preheat broiler.
2. In a large saucepan, melt 1 tablespoon of the butter, until sizzling.
3. Add onion, saute over medium heat 3 minutes or until tender.
4. Add remaining 3 tablespoons butter.
5. When butter is sizzling, whisk in flour.
6. Cook, stirring occasionally, 12 minutes or until mixture is golden brown.
7. Over medium heat, gradually whisk milk and chicken broth into flour-butter mixture, cook, stirring occasionally for 8-10 minutes or until mixture is thick and smooth.
8. Stir in tomatoes, rosemary, salt and pepper.
9. Reduce heat and add 1 cup each of the Monterey jack and cheddar cheese.
10. Cook, stirring occasionally for 3 minutes or until cheese is melted.
11. Stir in crabmeat and sherry.
12. Remove from heat.
13. Place drained, cooked pasta in a 3-quart baking dish; pour cheese mixture over pasta and mix well.
14. Sprinkle with mixture of remaining Cheddar and Monterey Jack cheese.
15. Broil about 5 inches from heat for 5-8 minutes or until cheese is bubbling.
16. Cool slightly before serving.