Ingredients:

For sauce
1 medium garlic clove
1/2 teaspoon salt
1 cup coarsely chopped fresh cilantro
1/4 cup olive oil
2 tablespoons fresh lemon juice
1/8 teaspoon cayenne

For steak
1 teaspoon ground cumin
1/2 teaspoon salt
1/2 teaspoon black pepper
2 lb skirt steak, cut crosswise into 3- to 4-inch pieces

Method:

Make sauce:
Mince garlic and mash to a paste with salt. Transfer to a blender and add remaining sauce ingredients, then blend until smooth.

Grill steak:
Stir together cumin, salt, and pepper in a small bowl. Pat steak dry, then rub both sides of pieces with cumin mixture.

Heat an oiled well-seasoned ridged grill pan over high heat until hot but not smoking, then grill steak in 2 batches, turning over occasionally, about 2 minutes per batch for thin pieces or 6 to 8 minutes per batch for thicker pieces (medium-rare). Serve steak drizzled with sauce.