Fill a 5-quart pot halfway full with water and bring to a boil. Add the kosher salt, and then the spinach. Cook the spinach until wilted, about 2 minutes, and then drain. Lightly press down on the spinach, but don’t extract all the water.
Add the spinach, tomato, and jalapeño to a blender and process until smooth.
Heat the ghee in a large, deep skillet over medium heat. Add the onion and cook until softened, about 3 to 5 minutes, and then add the garlic and ginger and cook 1 minute more, stirring constantly.
Stir in the spinach purée, salt, garam masala spice mix, coriander, cumin, turmeric, crushed red pepper flakes, and bay leaf. Bring to a simmer and cook 3 minutes, stirring frequently. Add the paneer cheese and cook 1 minute more, stirring constantly.
Turn off the heat and stir in the cream, lemon juice, and fenugreek. Cover the skillet and let it sit for 3 minutes.
Remove bay leaf and discard. Serve hot, with the Naan for dipping.