Season the Steak:
In a bowl, toss sliced ribeye with olive oil, lime juice, and all fajita seasoning ingredients. Let marinate while prepping veggies (or refrigerate up to 1 hour).
Cook the Vegetables:
Heat 1 tablespoon oil in a large skillet over medium-high heat. Add peppers and onion. Cook for 6–8 minutes, stirring occasionally, until softened and slightly charred. Remove and set aside.
Sear the Steak:
In the same skillet, add steak in a single layer (work in batches if needed). Sear 1–2 minutes per side until browned and cooked to desired doneness. Avoid overcooking for best tenderness.
Combine:
Return veggies to the skillet with the steak. Toss everything together for 1 minute to combine and heat through.
Serve:
Spoon steak and veggie mixture into warm tortillas. Serve with toppings like guacamole, sour cream, shredded cheese, salsa, or chopped cilantro.