In a sauce pan combine flour and water to make a paste that is smooth.
Add stock to pan and blend well. Then, add chicken and chilies, cumin, garlic, salt and pepper. Simmer this for 15 minutes.
Heat up oil in pan and cook tortillas then drain tortillas on paper towels.
In a casserole pan place a layer of tortillas then spoon in chicken mixture from pot now add some shredded jack cheese and continue to alternate tortillas layer with chicken mixture until no tortillas remain.
Sprinkle remaining jack cheese on top and place in 400 degree oven for 3-4 minutes then garnish with shredded lettuce, sour cream and diced tomatoes.