Cut tomatoes and jicama into bit size pieces. Mix in bowl with salad mix. Drain black beans and corn. Add to salad. Mix in jar of jalapeño dressing (if dressing is too spicy, mix with regular ranch dressing before adding to salad). Cut tortilla shells into strips using pizza cutter. Fry in oil until crisp. Remove from oil. Add salt and chili powder to strips for seasoning. Sprinkle strips on top of salad right before serving.