In a large bowl, whisk together the turmeric, cayenne, 1 teaspoon salt and 3 tablespoons oil. Gently, drop in the cubes of paneer and gently toss, taking care not to break the cubes if you're using the homemade kind. Let the cubes marinate while you get the rest of your ingredients together and prepped.
Thaw the spinach in the microwave in a microwave-safe dish, 5 minutes on high, then puree in a food processor until smooth. Alternatively, you can chop it up very finely with your knife.
Add the remaining 1 1/2 tablespoons oil to the pan. Add the onions, ginger, garlic and chile. Now here's the important part: saute the mixture until it's evenly toffee-coloured, which should take about 15 minutes. Don't skip this step - this is the foundation of the dish! If you feel like the mixture is drying out and burning, add a couple of tablespoons of water.
Add the garam masala, coriander and cumin. If you haven't already, sprinkle a little water to keep the spices from burning. Cook, stirring often, until the raw scent of the spices cook out, and it all smells a bit more melodious, 3 to 5 minutes.
Turn the heat off. Add the yogurt, a little at a time to keep it from curdling. Once the yogurt is well mixed into the spinach, add the paneer. Turn the heat back on, cover and cook until everything is warmed through, about 5 minutes. Serve.
*Paneer is very easy to make at home, and my recipe is quick, easy, and delicious. I also think homemade has a better texture than anything store-bought. If you'd like to buy it, this cheese is available in better supermarkets as well as specialty Asian markets. *If the milk doesn't separate juice some more lemons and add another tablespoon or two. Boost the heat again and the milk should separate. Stir in a motion that gathers the curds together rather than breaks them up.