In a small bowl, combine chili powder, cumin, coriander, salt, onion powder and pepper. Rub the spice mixture on the outside of the flank steak and place in the bottom of a slow cooker sprayed with nonstick cooking spray.
Top the flank steak with soy sauce, minced garlic, jalapeño, bell peppers and onion. Cover and cook on high for 5-6 hours or low for 8-9 hours, or until the steak can be easily shredded with two forks.
Thoroughly drain the meat and peppers and serve on tortillas with desired toppings.
Notes
*Nutrition info only includes meat and vegetables. Log tortillas and toppings separately.