ROAST BEEF: Rub serloin tip roast with 5-spice seasoning and sesame oil. Place beef, fat side up, on rack in shallow roasting pan. Insert meat thermometer so tip is in thickest part of beef and does not touch bone or rest in fat.
Do not add water. Do not cover. Roast in 325 degree oven to desired degree of doneness, planning about 21 to 30 minutes per pound (140 degrees rare; 160 degrees medium). Roast to 5 degrees below desired degree of doneness. Cover roast with foil tent and let stand 15 to 20 minutes before carving. Temperature will rise about 5 degrees. Serve with Blackberry Ketchup.
BLACKBERRY KETCHUP: Mix the berries with vinegar and water in a saucepan. Bring to a boil; lower heat to a simmer and cook 5 minutes. Sieve out seeds.
Return to saucepan and add brown sugar, cloves, ginger, cinnamon, cayenne pepper, salt, butter and grated tangerine rind. Simmer about 10 minutes, until thickened. Let cool. Makes approximately 2 cups.
Preparation time: 20 minutes
Baking time: about 2 hours