Heat oven to 350°F

Cook pasta as directed on package

While pasta is cooking, melt butter in large nonstick skillet on medium heat.

Add onions and cook and stir 6 minutes or until crisp-tender.

Blend in flour and cook and stir 1 minute

Gradually stir in broth and cook 5 minutes or until thickened, stirring constantly.

Add 1 cup shredded cheese; cook and stir 1 minute or until melted.

Drain pasta

Add to ingredients in skillet along with chicken and bacon. Mix well.

Transfer to 13x9 inch baking dish sprayed with cooking spray.

Top with remaining cheese and cover.

Bake 40 minutes, uncovering and topping with Parmesan for the last 10 minutes.

Top with tomatoes and cilantro.