Kabab-e Digi (کباب دیگی) — Persian Slow-Braised Sumac Kebab

• 700 gBeef sirloin, cut into 3 cm cubes (Trim excess surface fat; keep some marbling for tenderness)
• 450 gYellow onions, thinly sliced (About 3 medium; slice into half-moons)
• 650 gPotatoes, peeled and cut into 2.5 cm chunks (Waxy or all-purpose potatoes hold shape best)
• 14 gGround sumac (About 2 tablespoons; use fresh, bright-red sumac for best tartness)
• 10 gFine sea salt (About 1 3/4 teaspoons; adjust at the end to taste)
• 2 gBlack pepper, freshly ground (About 1 teaspoon)
• 45 mlNeutral cooking oil (About 3 tablespoons; sunflower, canola, or grapeseed)
• 360 mlWater (About 1 1/2 cups; add more only if needed during braise)

Instructions

1. 1

   Prepare the ingredients for even cooking: slice the onions into thin half-moons and cut the potatoes into 2.5 cm chunks. Pat the beef dry with paper towels so it browns instead of steaming. In a small bowl, mix the sumac, salt, and black pepper so seasoning distributes evenly during layering.

2. 2

   Heat a heavy pot or Dutch oven (4–5 L) over medium-high heat for 2 minutes. Add the oil and warm 30 seconds. Add the beef in a single layer (work in 2 batches if needed) and sear 3–4 minutes per side until browned. Transfer browned beef to a plate; keep the pot over medium heat.

3. 3

   Add the sliced onions to the same pot and sauté over medium heat for 8–10 minutes, stirring often, until softened and lightly golden. If the pot looks dry, add 1 tablespoon water and scrape up browned bits. These caramelized bits deepen the braising liquid and prevent a flat, boiled flavor.

4. 4

   Layer for a traditional slow braise: spread half the onions across the bottom, then add half the potatoes. Return all seared beef in an even layer, then top with the remaining potatoes and onions. Sprinkle the sumac-salt-pepper mixture evenly over the top so it perfumes the steam as the dish cooks.

5. 5

   Pour in 360 ml water around the edges (avoid washing seasoning off the top). Bring to a gentle simmer over medium heat, about 6–8 minutes. Once you see steady small bubbles, reduce heat to low, cover tightly, and braise for 75 minutes, maintaining a quiet simmer rather than a rolling boil.

6. 6

   After 75 minutes, check tenderness: the beef should yield easily to a fork and the potatoes should be soft but not disintegrating. If needed, continue cooking 10–20 minutes more on low. If the pot is drying out, add 60 ml water, cover, and return to a gentle simmer.

7. 7

   Uncover and cook 8–12 minutes over medium-low to reduce the liquid into a glossy sauce that clings to the onions. Taste and adjust salt if needed. Rest off heat, covered, for 10 minutes so juices settle. Serve family-style, spooning some of the tangy onion-sumac sauce over each portion.