Marinade:
4 garlic cloves, minced
1 jalapeño chile pepper, seeded and minced
1 teaspoon freshly ground cumin seed (best to lightly toast the seeds first, then grind them)
1 large handful fresh cilantro, leaves and stems, finely chopped (great flavor in the stems)
Kosher salt and freshly ground black pepper
2 limes, juiced
2 tablespoons white vinegar
1/2 teaspoon sugar
1/2 cup olive oil
mix that shit together and soak for at least a day.