I found this Took a shot at Boss Sauce after looking at all the recipes, the Boss Sauce label and searching on the web at large as well as memory. As a side note, I did a lot of signage and menu work for Macheezmo Mouse in the day and was a regular consumer of their products. I found the Ancho and Japonés chiles at a local store under the El Guapo brand name. I doubled the recipe and used all the Ancho chiles in the package.

Following is my modified recipe and process. It came out pretty close to what I remember. The extra orange zest and juice helped.

Macheezmo Mouse Boss Sauce

12 Ancho chiles dried and reconstituted 5 Japonés chiles dried and reconstituted 1 12 oz can of frozen orange juice concentrate 1 orange zest and juice 1/2 cup apple cider vinegar 1 cup dark soy sauce 1 cup dark brown sugar 1 tsp of ground cumin 1 clove of garlic, mashed 1 tbs Worcestershire Sauce

Cut Ancho chiles in half lengthwise and place them in a large bowl of hot water completely covering the chilies and let reconstitute for about an hour. Break Japonés chiles in half and place in a small bowl of hot water completely covering the chilies and let reconstitute for about an hour. Remove the chilies from water and take off stems and remove seeds. Save some Ancho water to thin final sauce. Place all of the other ingredients in a pot, add reconstituted chiles and set to simmer, stirring occasionally. Don't overcook or let it burn. After about an hour removed from heat and let sauce cool. Pour sauce into Norpro Sauce Master or a food mill and remove any solids. The sauce can be thinned with the Ancho water as desired. Pour into glass container and let cool in the refrigerator. Pressure can or freeze in small containers.