4 cloves garlic, chopped
1 tablespoon plus ½ teaspoon sugar
6 tablespoons light soy sauce
1 tablespoon dark soy sauce
1 tablespoon plus 1 teaspoon Asian sesame oil
2 tablespoons rice vinegar
5 green (spring) onions, minced, plus shredded green onion for garnish
1 teaspoon peeled and grated fresh ginger
2 tablespoons sesame seeds, toasted and crushed
½ teaspoon ground black pepper
1 teaspoon Sriracha chile sauce
1 tablespoon canola oil
1. Cut the beef across the grain into slides 1/8 inch thick. Working on a cutting board, use the side of the blade of a chef’s knife or cleaver to mash together three-fourths of the chopped garlic and the 1 tablespoon sugar, forming a paste. Place the paste in a bowl and stir in 3 tablespoons of the light soy sauce, the dark soy sauce, the 1 tablespoon sesame oil, 1 tablespoon of the vinegar, all but 1 tablespoon of the minced green onions, the ginger, 1 tablespoon of the sesame seeds, the black pepper, and 1 tablespoon water. Place the beef in a shallow bowl and pour the marinade on top. Mix well, cover, and refrigerate for 1-3 hours.
2. Meanwhile, make a dipping sauce. On a cutting board, use the side of the blade of a chef’s knife or cleaver to mash together the remaining chopped garlic and ½ teaspoon sugar, forming a paste. Place the paste in a bowl and whisk in the remaining 3 tablespoons soy sauce, the remaining 1 tablespoon vinegar, the chile sauce, the remaining 1 teaspoon sesame oil, the reserved 1 tablespoon minced green onions, the remaining 1 tablespoon sesame seeds, and 1 tablespoon water. Set aside until ready to serve.
3. Prepare a hot fire in a charcoal grill or preheat a stove-top grill pan over high heat.
4. Brush the grill rack or pan with the canola oil. Remove the beef from the marinade and pat dry. Discard the marinade. Working in batches, arrange in a single layer on the rack or pan. Sear, turning once, until crisp and brown on both sides, about 2 minutes per side. Wipe and oil the rack or pan between batches if necessary.
5. Transfer to a warmed platter, garnish with the shredded green onion and serve at once with the dipping sauce.