Cut the beef chuck into approximately 2-inch cubes and place them in a large bowl.

Season with salt and freshly cracked black pepper. Toss until the beef is evenly seasoned.

Heat a large, heavy-bottomed skillet or pot over medium-high heat. Add the neutral oil and heat until shimmering.

Add the beef in a single layer. Brown it on all sides for approximately 6 minutes. Work in batches if necessary to avoid overcrowding the pan.

Transfer the browned beef to a clean plate and set aside.

Reduce the heat to medium without draining the skillet. Add the chopped onion and cook for approximately 15 minutes, stirring regularly, until soft, golden, and caramelized.

Add the minced garlic and cook for another 2 minutes.

Stir in the garam masala, cumin, paprika, turmeric, ground mustard, cayenne, ginger, and cinnamon. Cook for about 1 minute, stirring constantly, until fragrant.

Add the tomato paste and stir until thoroughly incorporated with the onions and spices.

Pour in the apple cider vinegar. Cook for 2–3 minutes while scraping the bottom of the skillet to loosen the flavorful browned bits.

Pour in the beef stock and stir until combined.

Return the browned beef and any accumulated juices to the skillet. Bring the liquid just to a boil over medium heat.

Reduce the heat to medium-low and cover. Simmer the Beef Vindaloo for approximately 60 minutes, stirring occasionally and turning the beef as needed.

If the sauce becomes too thick during cooking, add beef stock 1–2 tablespoons at a time until it reaches your preferred consistency.

Once the beef is tender and the sauce has thickened, taste and adjust the salt if necessary. If you find the vinegar flavor stronger than you prefer, add ½–1 teaspoon packed brown sugar and simmer for another 2–3 minutes.

Serve hot over basmati rice with warm naan and plain Greek yogurt, if desired.