How to Make It
In a food processor, pulse the chiles and scallion whites until finely chopped.
In a medium saucepan, bring the vinegar, brown sugar, allspice and 2 tablespoons salt to a simmer, stirring to dissolve the sugar. Add the chile mixture to the saucepan and bring to a simmer. Simmer 1 minute then remove from the heat and let cool to warm. Hot sauce keeps in jars, chilled.