Place the cubed beef in a bowl. Add 1/2 cup plain yogurt, 4 minced garlic cloves, 2 tbs grated ginger, 1 1/4 tsp kosher salt, and 1/2 tsp freshly ground black pepper. Mix thoroughly to coat the beef. Cover and refrigerate for at least 30 minutes, up to 4 hours. If short on time, marinate 15 minutes.

Spice paste

Cook aromatics and spices

Heat 3 tbs vegetable oil or ghee in a large heavy-bottomed pot or Dutch oven over medium heat. Add 1/2 tsp whole cumin seeds (if using) and toast 20–30 seconds until fragrant. Add 1 cup finely chopped yellow onion and sauté until soft and golden, about 6–8 minutes, stirring occasionally. Add 3 minced garlic cloves and 1 tbs minced ginger; cook 1 minute until fragrant.

Build the spice paste

Stir in 2 tsp ground coriander, 1.5 tsp ground cumin, 1/2 tsp turmeric, 1 tsp paprika, and 1/4 tsp chili powder. Cook spices with the onion mixture for 1 minute to bloom the flavors. Add 2 tbs tomato paste and cook 1–2 minutes, stirring, until the tomato paste darkens slightly and becomes fragrant.

Brown the beef

Increase heat to medium-high. Remove the marinated beef from the refrigerator and let any excess marinade drip off. Add the beef to the pot in a single layer (work in batches to avoid crowding). Brown the beef cubes on all sides, about 3–4 minutes per batch. Do not fully cook through; you want a good sear for flavor. Transfer browned beef to a plate and repeat until all beef is browned.

Broth & simmer

Deglaze and combine

With the heat at medium-high, pour in 1/2 cup of the broth to deglaze the pot, scraping up browned bits with a wooden spoon. Add the remaining 1.5 cups broth and 1 cup diced canned tomatoes (including juices). Stir to combine, then return all browned beef to the pot. Add 1 bay leaf and the optional 2 cups cubed potatoes if using.

Simmer

Bring the pot to a gentle simmer, then reduce heat to low, cover partially, and simmer gently until the beef is tender, about 1 to 1 1/4 hours. Stir occasionally and check liquid level; add up to 1/2 cup water or broth if it becomes too thick. Taste at 45–60 minutes and adjust salt.

Finishing

Finish and serve

When the beef is tender and sauce has thickened to your liking, remove and discard the bay leaf. Stir in 1 tsp lemon or lime juice and 1/4 cup chopped fresh cilantro. Adjust seasoning with salt and freshly ground pepper to taste. If desired, swirl in 1/4 cup plain yogurt or cream for a silkier finish. Let rest 5 minutes before serving.

Serve hot over steamed rice, with naan or chapati and additional cilantro or yogurt on the side.