Spray slow cooker with non-stick cooking spray. Place steak in slow cooker with chiles, soup mix, lime juice, and water and cook on LOW for 6-8 hours.
Slice onion and bell peppers into strips. Heat a large skillet over medium high heat on stove top and add olive oil. Saute peppers and onion in skillet until tender.
Remove steak from slow cooker (I use a slotted spoon) and place meat, onions, bell peppers, and whatever other toppings you like on tortillas and serve.