Tahchin-e Sibzamini va Esfenaj (ته چین سیب زمینی و اسفناج) — Persian Golden Potato and Spinach Casserole

• 1200 gYukon Gold potatoes, peeled and cut into 3 cm chunks (Or other all-purpose potatoes)
• 12 gFine salt (For boiling water and seasoning potatoes)
• 120 mlWhole milk (Warm)
• 45 gUnsalted butter (Melted)
• 2 gGround black pepper (About 1 teaspoon)
• 30 mlExtra-virgin olive oil (About 2 tablespoons)
• 200 gYellow onion, finely diced (About 1 large onion)
• 12 gGarlic cloves, minced (About 4 cloves)
• 3 gGround turmeric (About 1 1/2 teaspoons)
• 450 gFresh spinach, roughly chopped (Stems removed if thick)
• 30 mlLemon juice, freshly squeezed (About 2 tablespoons, plus more to serve)
• 150 gHam, diced (Use halal-certified if needed; cut into 1 cm cubes)
• 200 gMozzarella cheese, shredded (Low-moisture mozzarella melts best)

Instructions

1. 1

   Heat the oven to 200°C (400°F). Grease a 23 x 33 cm (9 x 13 in) baking dish with 10 ml olive oil. Bring a large pot of water to a boil; add the potatoes and 8 g of the salt. Boil 18–22 minutes, until a knife slides in easily without resistance.

2. 2

   While the potatoes cook, make the filling. Warm 30 ml olive oil in a wide skillet over medium heat. Add the onion and cook 8–10 minutes, stirring, until soft and lightly golden. Add garlic and cook 45–60 seconds until fragrant, then stir in turmeric for 20 seconds to bloom its color.

3. 3

   Add the spinach in 2–3 batches, tossing each batch until wilted before adding more. Cook 4–6 minutes total, until the pan is mostly dry and the spinach is tender. Season with 4 g salt and stir in 30 ml lemon juice. Transfer to a bowl and cool 5 minutes so it doesn’t steam the layers.

4. 4

   Drain the potatoes thoroughly and return them to the hot pot. Let them steam-dry 2 minutes over low heat, shaking once, to prevent a watery mash. Mash until smooth, then mix in warm milk, melted butter, remaining 4 g salt, and black pepper. Taste and adjust seasoning.

5. 5

   Assemble the casserole. Spread half the mashed potatoes evenly in the prepared dish. Spoon the turmeric spinach mixture over the potatoes in an even layer, then scatter the diced ham across the spinach. Sprinkle 150 g mozzarella over the filling, keeping the remaining 50 g for the top.

6. 6

   Dollop the remaining mashed potatoes over the cheese and gently spread to seal the filling. Sprinkle the remaining 50 g mozzarella on top. Bake 25 minutes at 200°C (400°F), then switch to broil/grill on high for 2–4 minutes until the top is deeply golden and bubbling.

7. 7

   Rest the casserole 10–15 minutes before slicing; this helps the layers set cleanly. Finish with an extra 5–10 ml lemon juice over the top just before serving for a bright contrast to the rich potatoes and cheese. Serve hot or warm.