In a large skillet, saute onion, green pepper and jalapeno in oil until the onion is tender.
Stir in chicken.
Remove from heat and set aside
For sauce, melt butter in pan.
Stir in flour until smooth
Add broth, cumin, garlic powder, alt and pepper
Bring to a boil
Cook and stir for two minutes or until thickened and bubbly
Remove from heat
Stir in sour cream
Add 1 cup sauce to the chicken mixture
Grease a 13 x 9 x 2 in pan
Spoon 1/2 cup chicken mixture onto each tortilla roll, roll it up and place seam side down in pan
Repeat for all tortillas
Spoon remaining sauce over enchiladas
Bake uncovered at 350 for 15 minutes or until the sauce is bubbly
Sprinkle with cheese
Bake 5-10 minutes longer