Lime, garlic, and salt marinade for 4 hours is traditional. The people who claims to have made it first also put in pineapple juice.
It’s tough meat, and the acid softens it up and the thinner cut makes it easier to eat.
Eat just the cooked meat with corn tortillas heated on the grill—no vegetables or beans or cheese or sour cream, except for homemade pico de gallo.
Frijoles en olla eaten out of a paper cup is the traditional side.