Gas-Grilled Sirloin Steak Tips with Garlic, Ginger and Soy Marinade

1. Making the Marinade: Combine the soy sauce, oils, garlic, ginger, sugar, zest, red pepper, and scallion in a small bowl. 2. Preparing the Steak Tips: Combine marinade and meat in gallon-size zipper-lock bag; press out as much air as possible and seal bag. Refrigerate 1 hour, flipping bag after 30 minutes to ensure that meat marinates evenly. 3. About halfway through marinating time, turn burners on grill to high, close lid, and heat grill until hot, about 15 minutes. 4. Remove steak tips from marinade and pat dry with paper towels. Grill, covered, until well seared and dark brown on first side, about 4 minutes. Using tongs, flip steak and grill until second side is well seared and thickest part of meat is slightly less done than desired, 4 to 5 minutes for medium-rare (about 130 degrees on instant-read thermometer), 6 to 8 minutes for medium (about 135 degrees); if exterior of meat is browned but steak is not yet cooked through, move steak to cooler side of grill and continue to grill to desired doneness. 5. Transfer steaks to cutting board; tent loosely with foil and let rest 5 minutes. Slice steak very thinly on the bias; serve immediately with orange wedges.