In a large skillet with high sides, heat the butter over high heat and quickly sauté the spinach just until it starts to wilt (do this in batches if necessary). Remove to a plate and set aside.
Turn the heat down to medium-high, and heat more butter in the same skillet. Add the paneer, sprinkle with salt and fry until browned on one side. Toss and sauté for a few moments longer, then remove to a bowl and set aside.
Add a little more butter to the skillet and add the onion, garlic, ginger and chilies. Sauté until the onions begin to turn translucent. Add the turmeric and sauté 1 to 2 minutes longer. Stir the cream into the onion mixture, then add the yogurt and cook until the mixture comes together and is heated through.
Return the spinach (leaving accumulated liquid behind) and paneer to the skillet and toss until incorporated with sauce. Taste and correct seasoning with salt. Serve with grilled naan or hot basmati rice.