Rinse and dry steak. Rub with 1 tablespoon of olive oil, then season with 1 envelope of fajita mix. Let marinate at least 2 hours, up to 24 hours.
Cook steak on med high grill (or in skillet over med high) to med, turning a couple of times. Remove to cutting board and let rest 15 minutes. Thinly slice against the grain (as thin as you can without it falling apart).
Cut all veggies (except grape tomatoes) to about 1/2 inch pieces. In large skillet over med heat, cook garlic (minced) until fragrant. Add veggies (except tomatoes) and cook just until starting to get tender. Add remaining seasoning mix and oil.
Mix pasta and steak with skillet contents. Add tomatoes and feta cheese crumbles. Season with salt and pepper to taste. Continue on stove til everything is hot through. Add pasta water to skillet to get consistency you want for the sauce. Serve with a crusty bread and a light salad for a great meal.