Mix together in a medium size pot:
2 cups sugar
1 tablespoon salt
1 Tablespoon chili flakes or more to taste
1 ½ teaspoons freshly ground black pepper
1 cup yellow prepared mustard
1 ¼ cups ketchup
½ cup water
12 ounces white vinegar
Cook over medium heat for 30 minutes, stirring occasionally.
For a thicker sauce:
Mix together in a small bowl:
¼ cup sugar
¼ cup corn starch
¼ cup cold water
Stir into sauce and simmer for another 30 minutes.
