I made it and followed all the directions almost exactly. Only I used half butter, half oil. I also fried the onions until browned it took about 20 minutes, but the flavor was so worth the extra cooking time. I had no idea what sweet curry powder was so I put in about 1/8 tsp each of cardamom, cinnamon, cloves, garam masala, and nutmeg. I used full fat yogurt. And finally I used a 1lb package of thawed frozen spinach that I squeezed the water out of. It was delicious. It was more spinachy and less dippy but was totally delicious and plan on making it again and again.
We had it as a side dish with chicken kebabs and rice because I made it with a bit less yogurt. Chopped the spinach and made about 1/4 recipe to serve the 2 of us (I just estimated the conversions - a dash of this, a dash of that). Really just barely wilted the spinach - took it off heat after about a minute. Great spice mix, intense fresh flavor, and the hotsauce gives it some bite. Oh, and I added a little pinch of fresh minced mint with the spices.
this didnt turn out very well for me. i may have cooked it too long but it was watery and a little bitter tasting. it was ok after i drained a lot of the water off, hopefully it will work out better for the rest of you.