Make sauce the night before. In skillet, melt butter and cook onions and bell peppers (optional) until soft, but not brown. Add flour by sprinkling and cook while stirring for about 3 minutes. Remove from heat, add broth and half and half, while whisking. Bring the sauce to a boil and simmer over moderate heat.
The next day, warm up sauce; it should be somewhat thick. In large bowl, mix sauce and chicken strips together. Use just enough sauce to coat chicken and maybe a little more.
Place tortilla in greased skillet and spread chicken mixture and cheese on top. Place another tortilla on top. Cook until brown.
Serve with sour cream, shredded lettuce and Pico de Gallo (Mexican salsa) on the side.
Cajun Country -- New Iberia, Louisiana