How to Make It
In a small bowl, whisk the olive oil with the garlic, thyme and rosemary. Set the spareribs in a baking dish and season with salt and pepper. Rub the garlic mixture all over the ribs and cover with plastic wrap; refrigerate for at least 8 hours or overnight.
In a small saucepan, simmer the vinegar over moderately low heat until reduced to 1/4 cup, about 8 minutes.
Light a grill or preheat the broiler. Grill the ribs over moderately high heat, turning occasionally, until lightly charred and cooked through, 15 to 20 minutes. Brush the ribs with some of the reduced vinegar and grill, turning, until nicely glazed, about 5 minutes longer. Cut the ribs between the bones, transfer to a platter and serve.