In a bowl, combine the beer, garlic, and a heavy seasoning of salt and pepper. Pat the steak dry and place in a large resealable bag. Pour the marinade over, seal and let rest in fridge for 1 to 8 hours.
When ready to cook, preheat the grill to medium-high and clean grate.
Toss the veggies with 2 tbs oil and season with alt and pepper. Arrange in a grill pan or with tongs, grill until tender and slightly charred in spots.
Meanwhile, remove the steak from marinade and pat dry with paper towels. Coat in remaining 1 tbs oil and grill 8 to 10 minutes flipping once half way through.
Cover the steak with foil and allow to rest for 10 minutes before slicing thinly against the grain.
Serve with charred veggies, fresh salsa and other desired toppings.
You can also heat the tortillas over the grill while the steak rests if desired.