• 5 tablespoons ghee
• 1.5 tablespoon black mustard seeds
• 2 large onions, peeled, halved lengthwise and thinly sliced crosswise
• 4 cloves garlic, mashed
• 1 ¼ teaspoons of salt plus more, to taste
• 1 kg potatoes, peeled and cut into ¾-inch to 1-inch cubes
• 1 kg spinach
• A pinch of cayenne pepper (use an extra pinch or two if you like a lot of heat)

https://www.panningtheglobe.com/saag-aloo-indian-spinach-and-potatoes/