Serve this rich gravy with our Roasted Pork Loin.
Pour off excess fat from roasting pan (reserving dark liquid and browned bits). Add chicken broth to pan; cook over medium-high heat, scraping up browned bits, until liquid has reduced by half, 5 to 7 minutes.
Meanwhile, in a small bowl, whisk flour with water.
Reduce heat to medium; whisk in flour mixture and balsamic vinegar until sauce is completely smooth and has thickened, 1 to 3 minutes.
