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.
Place a large nonstick skillet over medium heat, and add the paneer as the pan warms. In a couple of minutes give the pan a toss; each piece of paneer should be browned on one side. Fry another minute or so, and then remove the paneer from the pan onto a plate.
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.
Add the spinach and stir well, incorporating the spiced onion mixture into the spinach. Add a little salt and 1/2 cup of water, stir, and cook about 5 minutes with the lid off.
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.
Line a large colander with a large double layer of cheesecloth, and set it in your sink.
In a large wide pot, bring the milk to a gentle boil over medium heat, stirring frequently to avoid burning the bottom (a nonstick pot works really well for this purpose). This will take a little while so be patient!
Add the lemon juice and turn the heat down to low. Stirring gently, you should almost immediately see the curds (white milk solids) and whey (the greenish liquid) separate. Don't fret, this is perfect!
Remove the pot from the heat and carefully pour the contents into the cheesecloth-lined colander. Gently rinse with cool water to get rid of the lemon flavor. At this point, you could squeeze out some of the liquid, and serve with some honey and some nuts, almost like a fresh ricotta!
Grab the ends of the cheesecloth and twist the ball of cheese to squeeze out the excess whey. Tie the cheesecloth to your kitchen faucet and allow the cheese to drain for about 5 minutes.
Twisting the ball to compact the cheese into a block, place it on a plate with the twisted part of the cheesecloth on the side (this will ensure your block of cheese is nice and smooth!) and set another plate on top. Weigh the second plate down with cans of beans or a heavy pot. Move to the refrigerator and let it sit about 20 minutes.
Combine the cinnamon sticks, cloves, green cardamom seeds, black cardamom seeds, if using into a spice grinder or coffee grinder and grind until fine. Store the spice mix in an airtight container away from direct sunlight.
*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.