Beef Fajitas

We had some delicious beef fajitas at a friend's house the other weekend and I haven't been able to stop thinking about them.  Amid all the chicken we eat, I wanted to add beef to the menu and not be one of our regulars.  This recipe is fantastic!!  I love that you marinate the veggies, as well.  So delicious.  I'm going to have to make it again soon because I still can't stop thinking about it!

Beef Fajitas
adapted from The Pioneer Woman

1 whole beef flank steak (I think I used a top round or something that didn't look very fatty)
1/2 cup olive oil
3 tbsp Worcestershire sauce
1/3 cup lime juice
3 cloves garlic, minced
1 tbsp cumin
1 tbsp chili powder
1/2 tsp red pepper flakes
1 tsp salt
1/2 tsp black pepper
1 tbsp sugar
1 large onion, halved and sliced
1 whole red bell pepper, sliced
1 whole green bell pepper, sliced
flour tortillas, warmed
shredded cheese
salsa
sour cream
guacamole

In a bowl, mix together olive oil, Worcestershire sauce, lime juice, garlic, cumin, chili powder, red pepper flakes, salt, pepper and sugar until combined.  Take 2 baking dishes (I used aluminum disposables for easy clean up) and put the sliced veggies in one and the steak in the other.  Pour half the marinade over the steak and the rest over the veggies.  Turn the steak to coat both sides and toss the veggies to coat evenly.  Cover with plastic wrap and refrigerate at least 2 hours.  Preheat grill to medium-high heat.  Put the steak on the grill and cook on each side for just a few minutes, and remove .  Meanwhile, heat a skillet over medium-high heat and add the veggies, with the leftover drippings from the dish they marinated in.  Cook for a few minutes until the onions get a little wilty and the peppers get a little charred.  Slice up the meat and serve with the tortillas, etc!