1. Blend soup mix with chili powder. Toss beef strips in soup mixture.
2. Heat half of the oil in a large nonstick skillet set over medium-high heat.
3. Add beef to pan in two batches, adding in remaining oil as necessary.
4. Brown on all sides for about 1 minute per batch.
5. Add in peppers, water and any remaining soup mixture.
6. Cook, stirring often, for 1 minute or until sauce has thickened slightly.
7. Remove from heat and stir in green onions.
8. Divide meat mixture, cheese and sour cream evenly between tortillas.
9. Fold and roll to encase filling.