Slice the bell peppers and onion into thick strips. Warm oil in pan over medium-high heat and add veggies.
Saute the fajita veggies for 8-10 minutes, until soft. Season with dried oregano and salt. Serve warm immediately.
Enjoy as a topping on tacos, burrito bowls, taco salads, burritos, and more! Store leftovers for up to 5 days.