Whisk together lime juice, garlic, red-pepper flakes, and 1/4 teaspoon salt, then add oil in a slow stream, whisking well. Whisk in cilantro.
Prepare a gas grill for direct-heat cooking over medium-high heat. Pat pork dry and season with salt and pepper. Oil grill rack, then grill pork chops, covered, turning over once, until just cooked through, 5 to 6 minutes total. Serve drizzled with some vinaigrette, and with remainder on the side.
Cooks' note: If you aren't able to grill outdoors, chops can be cooked in a hot lightly oiled large (2-burner) ridged grill pan over moderately high heat. Makes 4 servings.