Pour in apple cider vinegar to deglaze skillet. Cook 2 to 3 minutes, stirring constantly and scraping up any browned bits that might be stuck to bottom of skillet.
Pour in beef stock and gently stir to incorporate. Return browned beef to skillet and let mixture cook over medium heat until liquid begins to boil.
When liquid just begins to boil, reduce heat to medium-low. Cover skillet with lid and let beef and sauce simmer 60 minutes. While simmering, stir mixture occasionally and flip beef as needed to ensure even cooking. Note: if sauce becomes too thick, add 1 to 2 tablespoons beef stock as needed to thin sauce back out. Stir to fully incorporate stock before adding more.
When beef is fully cooked and tender, and sauce has thickened to desired consistency, taste sauce and adjust salt as needed. Note: if vinegar flavor is too strong, stir in ½ to 1 packed teaspoon brown sugar and simmer another 2 to 3 minutes.
When satisfied with flavor of sauce, remove skillet from heat. Divide beef vindaloo into equal portions and serve immediately over basmati rice with warmed naan and 1 to 2 dollops plain Greek yogurt if desired.
Pour in apple cider vinegar to deglaze skillet. Cook 2 to 3 minutes, stirring constantly and scraping up any browned bits that might be stuck to bottom of skillet.
Pour in beef stock and gently stir to incorporate. Return browned beef to skillet and let mixture cook over medium heat until liquid begins to boil.
When liquid just begins to boil, reduce heat to medium-low. Cover skillet with lid and let beef and sauce simmer 60 minutes. While simmering, stir mixture occasionally and flip beef as needed to ensure even cooking. Note: if sauce becomes too thick, add 1 to 2 tablespoons beef stock as needed to thin sauce back out. Stir to fully incorporate stock before adding more.
When beef is fully cooked and tender, and sauce has thickened to desired consistency, taste sauce and adjust salt as needed. Note: if vinegar flavor is too strong, stir in ½ to 1 packed teaspoon brown sugar and simmer another 2 to 3 minutes.
When satisfied with flavor of sauce, remove skillet from heat. Divide beef vindaloo into equal portions and serve immediately over basmati rice with warmed naan and 1 to 2 dollops plain Greek yogurt if desired.
