Spray a heavy bottom pot with cooking spray, and place over medium heat. Saute onion, green bell pepper, red bell pepper and okra until soft. Season with a pinch of Cajun seasoning. Remove from pot, and set aside.
Coat pot with cooking spray (turn off flame while spraying), and return to medium high heat. Saute chicken until no longer pink, and juices run clear. Season with 1 tablespoon Cajun seasoning. Stir in crawfish, and cook for 1 minute. Remove from pot, and set aside with vegetables.
Melt butter in pot on medium low heat. Whisk in flour until roux begins to bubble. Add milk, and whisk until smooth. Add half-and-half, and whisk continuously until mixture thickens enough to coat the back of a spoon. Add a pinch of salt. Stir in shredded Cheddar cheese a little at a time until well incorporated. Add grated Romano cheese and whisk until incorporated. Season with chili powder and paprika. Stir in chicken, crawfish and vegetable mixture. Simmer for 5 minutes.
This dish is excellent served on a spiral shaped long or short pasta, but my favorite way of serving it is in a hollowed bread bowl made of a crusty bread with a lighter center (like a round ciabatta). Season the bread bowl with a little butter or olive oil and roasted garlic or garlic salt, then toast the open bread bowl under the broiler until just browned. Scoop this stew into the bread bowl and top with a little romano cheese. This dish is quite decadent, but oh-so-good. All other courses should be light to complement this very heavy main dish. Excellent with a semi-dry Gewurztraminer or Riesling to balance the richness of the spicy sauce.