Grilled Sweet and Spicy Hoisin Glazed Pork Tenderloin Roast

FOR THE TENDERLOIN: Lay tenderloins on cutting board, flat side (side opposite where silver skin was) up. Holding thick end of 1 tenderloin with paper towels and using dinner fork, scrape flat side lengthwise from end to end 5 times, until surface is completely covered with shallow grooves. Repeat with second tenderloin. Dissolve 3 tablespoons salt in 1½ quarts cold water in large container. Submerge tenderloins in brine and let stand at room temperature for 1 hour.

FOR THE SWEET AND SPICY HOISIN GLAZE: Meanwhile, heat oil in small saucepan over medium heat until shimmering. Add in garlic, ginger, and pepper flakes; cook until fragrant, about 30 seconds. Whisk in hoisin and soy sauce until smooth. Remove pan from heat and stir in vinegar. Transfer ⅓ cup glaze to bowl for grilling; reserve remaining glaze for serving.

Remove tenderloins from brine and pat completely dry with paper towels. Lay 1 tenderloin, scraped side up, on cutting board and lay second tenderloin, scraped side down, on top so that thick end of 1 tenderloin matches up with thin end of other. Spray five 14-inch lengths of kitchen twine thoroughly with vegetable oil spray; evenly space twine underneath tenderloins and tie. Brush roast with vegetable oil and season with pepper.

FOR A CHARCOAL GRILL: Open bottom vent completely. Light large chimney starter filled with charcoal briquettes (6 quarts). When top coals are partially covered with ash, pour into steeply banked pile against side of grill. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.

FOR A GAS GRILL: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Leave primary burner on high and turn off other burner(s).

Clean and oil cooking grate. Place roast on cooler side of grill, cover, and cook until meat registers 115 degrees, 22 to 28 minutes, flipping and rotating halfway through cooking.

Slide roast to hotter part of grill and cook until lightly browned on all sides, 4 to 6 minutes. Brush top of roast with about 1 tablespoon glaze and grill, glaze side down, until glaze begins to char, 2 to 3 minutes; repeat glazing and grilling with remaining 3 sides of roast, until meat registers 140 degrees.

Transfer roast to carving board, tent loosely with aluminum foil, and let rest for 10 minutes. Carefully remove twine and slice roast into ½-inch thick slices. Serve with remaining glaze.