How to Make It
In a medium bowl, mix the red wine and olive oil with 1 tablespoon and 2 teaspoons of the garlic. Add the skirt steak and toss to coat, then let stand for 15 minutes.
Meanwhile, in another bowl, toss the tomatoes with the jalapeños, onion, cilantro, lime juice and the remaining 1 teaspoon of garlic. Season the salsa with salt and pepper.
Light a grill or heat a grill pan. Remove the steak from the marinade; season with salt and pepper. Grill over moderately high heat, turning once, until medium rare, about 4 minutes. Transfer to a cutting board; let stand for 3 minutes.
Thinly slice the steak across the grain and arrange on a platter. Serve with the salsa, avocado slices, shredded cheese, sour cream and warm tortillas.