In a small bowl, add soy sauce, molasses, miso, mustard, paprika and lime zest. Whisk to combine.

Pour into a small saucepan and set over medium-high heat.

Allow mixture to come to a boil, then remove from heat and immediately add in cubed butter, one piece at a time, stirring until no streaks of butter remain.

Taste. Season, to taste, with salt and pepper (it may or may not need more salt, depending on how salty your miso is).