Ingredients

  • 2 tablespoons black peppercorns
  • 1 1/2 tablespoons kosher salt
  • 2 tablespoons olive oil
  • 1 (2 1/2-lb) center-cut beef tenderloin roast, trimmed and tied
  • 1 1/2 lb fingerling or baby Yukon Gold potatoes (about 16), halved lengthwise
  • 1/2 lb pearl onions (about 16), blanched in boiling water 1 minute, drained, and peeled
  • 12 garlic cloves
  • 2 tablespoons minced fresh sage
  • 1/4 cup extra-virgin olive oil
  • 1/2 cup sour cream
  • 6 bacon slices, cooked and crumbled
  • 1/4 cup thinly sliced fresh chives
  • Special equipment: 12-inch-wide heavy-duty aluminum foil; a 22 1/2-inch kettle grill with a hinged top rack (if using charcoal); a large chimney starter (if using charcoal); long metal tongs; a 17- by 12 1/2- by 3 1/2-inch disposable aluminum roasting pan (if using charcoal); an instant-read thermometer

Method

  • Coarsely crack peppercorns (see cooks' note, below).
  • Stir together pepper and salt in a small bowl, then add oil and stir until combined well.
  • Rub spice mixture all over beef.
  • Tear off 8 (2-foot-long) sheets of heavy-duty foil and arrange in 2 stacks of 4.
  • Divide potatoes, onions, garlic, and sage between stacks, arranging in 1 layer in center of foil, then drizzle each with 2 tablespoons oil and season with salt and pepper.
  • Working with top sheet of foil, fold each side over potato mixture to enclose, then turn package a quarter turn and repeat folding and turning package with each piece of remaining foil.
  • Make second hobo pack in same manner.
  • Open vents on bottom of grill.
  • Light charcoal (80 to 100 briquettes) in chimney starter.
  • Leaving about one quarter of grill free of charcoal, bank lit charcoal across rest of grill so that coals are about three times higher on opposite side.
  • Charcoal fire is medium-hot when you can hold your hand 5 inches above rack over area where coals are piled highest for 3 to 4 seconds.
  • Using long metal tongs, lift up one hinged side of rack and put hobo packs, folded sides down, on portion of bottom rack with no coals on it.
  • (One side of packages will be in direct contact with coals.)
  • Cook hobo packs, turning a quarter turn with tongs every 15 minutes, 45 minutes total.
  • While hobo packs are cooking, sear beef on lightly oiled grill rack directly over hottest part of coals, uncovered, turning occasionally and, if necessary, moving around grill to avoid flare-ups, until well browned, 12 to 15 minutes total.
  • Move beef to coolest part of grill, then cover with inverted roasting pan and grill, turning occasionally, until thermometer inserted diagonally into center registers 120F for medium-rare, about 10 minutes.
  • Transfer beef to a cutting board and let stand, loosely covered with foil, 15 minutes.
  • Preheat all burners on high, covered, 10 minutes.
  • Reduce heat to moderately low on 2 burners if your grill has 3 (or 1 burner if your grill has 2) and cook hobo packs, folded sides down, on grill rack, covered with lid, over moderately low burner(s) 40 minutes.
  • Meanwhile, sear beef on lightly oiled grill rack over remaining burner on high, covered with lid, turning over occasionally, until well browned, 12 to 15 minutes total.
  • Reduce heat to moderate and cook beef, covered with lid, turning over occasionally, until thermometer inserted diagonally into center registers 120F for medium-rare, about 10 minutes.
  • Transfer beef to a cutting board and let stand, loosely covered with foil, 15 minutes.
  • Thinly slice beef, then remove potato mixture from packages and serve with sour cream, bacon, and chives.