Two 2½- to 3-pound racks St. Louis-style spareribs, trimmed, membrane removed, racks cut into 2-rib sections
2 teaspoons kosher salt
1 tablespoon vegetable oil
1 teaspoon pepper
1/4 cup extra-virgin olive oil
2 garlic cloves, minced
1 teaspoon minced rosemary
2 tablespoons lemon juice
Ribs: Pat ribs dry with paper towels. Rub evenly on both sides with salt, place on wire rack set in rimmed baking sheet. Let stand at room temperature for 1 hour.
Vinaigrette: Combine oil, garlic, and rosemary in small bowl, microwave 30 seconds until fragrant and just starting to bubble. Stir in lemon juice, set aside.
Charcoal grill: Open bottom vent completely, light large chimney starter filled with charcoal briquettes. When top coals are partially covered with ash, pour evenly over grill. Set cooking grate in place, cover, open lid vent completely. Heat grill until hot.
Gas grill: Turn all burners to high, cover, heat grill until hot. Turn all burners to medium-high.
Clean and oil grate. Brush meat side of ribs with oil, sprinkle with pepper. Place ribs meat side down on grill. Cover and cook until meat side begins to develop spotty browning and light but defined grill marks, 4-6 minutes. Flip ribs and cook, covered, until second side is lightly browned, 4-6 minutes, moving ribs as needed to ensure even browning. Flip again and cook 4-6 minutes, covered, until meat side is deeply browned with slight charring and thick ends of ribs register 175°-185°F.
Transfer ribs to cutting board, let rest 10 minutes. Cut ribs between bones and serve, passing vinaigrette separately.
REMOVING THE MEMBRANE FROM SPARERIBS
The papery membrane on the rack’s underside is chewy and unpleasant to eat. To remove it, slip the tip of a paring knife under edge of the membrane on each rack to loosen it (see below).
Gripping loosened edge with a paper towel, slowly pull off the membrane. It should come off in a single piece.