
Our best carne asada tacos are made with grill-friendly flank or skirt steak and get punchy flavor from a citrusy marinade with cilantro and garlic.
Combine garlic, cilantro, orange juice, lager, lime juice, oil, salt, pepper, vinegar, cumin, and chile powder in a large baking dish or 1-gal. resealable plastic bag. Add steak and turn to coat in marinade. Cover (or seal) and chill, turning occasionally, at least 10 hours and up to 1 day.
Prepare a grill for medium-high heat; oil grate. Grill onion halves, chiles, and tomatillos, turning often, until charred and tender, 10–15 minutes for onion and tomatillos, 8–12 minutes for chiles.
Transfer vegetables to a blender and add garlic, lime juice, salt, pepper, garlic powder, cumin, 1 cup cilantro, and 3 Tbsp. oil. Carefully blend until salsa is mostly smooth (some texture is good but make sure there are no large chunks).
Remove steak from marinade, letting excess drip back into dish (or bag); discard marinade. Grill steak, turning every minute or so, until charred and an instant-read thermometer inserted into thickest part registers 140° for medium, about 5 minutes. Transfer to a cutting board and let rest 10 minutes.
Thinly slice steak against the grain, then cut into bite-size pieces. Transfer to a bowl and sprinkle with sea salt.
Top tortillas with some steak, salsa, cilantro, and chopped onion. Serve with lime wedges for squeezing over and remaining salsa alongside.
Do ahead: Salsa can be made 1 day ahead. Transfer to an airtight container; cover and chill. Loosen with a splash of water if needed before serving.