Step #1 Dry the meat with paper towels & rub the meat with the orange zest.
Step #2 In a small bowl, soy sauce, mix the sugar, sake & 1 tbsps of the oil.
Step #3 Rub this into the beef.
Step #4 Wrap the meat tightly with plastic wrap, place on a platter & put in the fridge overnight.
Step #5 Remove meat from the refrigerator 3 hrs before cooking.
Step #6 Preheat the oven to 425F degrees F.
Step #7 Unwrap the meat & rub with remaining 1 tbsps of oil & place on a metal roasting pan.
Step #8 Roast the meat on the bottom rack in the oven for 15 mins, carefully turning it once with tongs.
Step #9 Continue roasting for another 15-20 mins longer, until an instant read thermometer inserted in the thickest part of the meat registers 125 degrees F.
Step #10 for medium-rare.
Step #11 Remove meat from the oven, cover loosely with foil wrap & set aside to rest for 15 mins before carving.
Step #12 Transfer meat to a cutting board & cut 1/2" thick slices & arrange on dinner plates.
Step #13 Pour all of the accumulated juices & 1/4 c of water into the roasting pan & bring to a boil on the stove top over a moderately high heat.
Step #14 Stir to scrape the browned bits from the bottom of the pan & cook this until reduced slightly, about 1 min.
Step #15 Pour some of the sauce over the meat & serve as soon as possible.