Preheat oven to 350°F.
Coat steak in lime juice.
In a small bowl, mix together cumin, garlic powder, chili powder, smoked paprika and Celtic Sea Salt. Rub into the steak. Rest for 30 minutes.
In a large, hot skillet, spritz with cooking spray (omit cooking spray if using cast iron) and sear meat on all sides, about 1 minute per side.
Transfer steak to an oven-safe dish (if you used cast iron, you can put skillet directly in oven) and roast 10-30 minutes, depending on the thickness of the steak. Once desired temperature is reached, (see note below) let steak sit at least 10 minutes before slicing.
While steak is resting, spritz another skillet with cooking spray and saute peppers and onions on medium to high heat until softened.
Slice steak and serve with peppers and onions. Garnish with lime wedges.