In a 2-quart saucepan, combine milk, carrot, celery, onion, parsley, peppercorns, hot pepper sauce, bay leaf and nutmeg. Bring to boil. Reduce heat to low; simmer 10 minutes. Strain, reserving liquid. Melt butter in 2-quart saucepan over low heat. Blend in flour. Gradually add reserved liquid; cook, stirring constantly, until thickened. Remove from heat. Add Parmesan and Romano cheeses; stir until blended. Pour over pasta; toss well. Combine Cheddar and Mozzarella cheese. In buttered 2-quart casserole, layer 1/2 of pasta mixture, Cheddar cheese mixture and remaining pasta mixture. Sprinkle with chili powder. Bake at 350°F for 25 minutes or until hot.