Heat broiler. Coat a 2-quart broiler-proof baking dish with nonstick cooking spray.
Place chicken breast on greased broiler pan and broil 4 inches from flame for 6 to 7 minutes per side until internal temperature registers 160° F. Remove to plate and cut into 1/2-inch pieces. Keep warm.
In a large nonstick skillet over medium heat, cook bacon about 5 minutes until crisp. Chop and reserve.
Cook pasta following package directions, about 12 minutes. Drain.
Stir flour into milk and combine with soup and garlic salt in a medium-size saucepan. Simmer for 2 minutes until thickened; stir in 3/4 cup of the cheese.
Return pasta to pot and stir in chicken and soup mixture. Spoon into prepared baking dish and top with bacon and remaining 1/2 cup cheese.
Broil 4 inches from flame for 2 to 3 minutes or until heated and lightly browned on top. Serve immediately.
