Add sugar, mustard, tomato paste, soy sauce and Worcestershire sauce, stir just enough to incorporate. For stove top, reduce heat to low and let mixture simmer about 10 minutes. Stirring every few minutes. For Instant Pot, close the lid and venting knob, set Manual cook for 5 minutes. After 10 minutes of natural pressure release, carefully open the valve to release remaining pressure. Carefully open the lid, give everything a stir and let it sit for another 5 minutes to allow the sauce to reduce slightly.