PLACE pizza dough in lightly oiled pan; cover until ready to use. (Refrigerate if not using within 2 hours.)
PLACE peppers in saucepot. Add sugar and vinegar; mix well. Cook until slightly thickened. Puree in blender; return to saucepot. Stir in barbecue sauce. Bring to simmer on low heat; keep warm.
GRILL sausages until done; keep warm.
FOR each serving: Roll and stretch a pizza dough ball into 10- to 12-inch round. Grill until crust is lightly charred on both sides.
SPREAD 1 flatbread with 1-1/2 oz. sauce; top with 1/2 oz. frisee and 1 sausage link. Fold in half; secure with wooden skewer, if desired.