To a pot of boiling water, add a little salt and then spinach leaves to it. Blanch the spinach leaves for 2 to 3 minutes until wilted.
Take them out and put them in ice-cold water. This helps the leaves in retaining their green colour.
To a blender, add the blanched spinach along with tomato, 3 cloves of garlic, ginger and green chilli.
Puree to a smooth paste and set aside.

Heat a pan on medium heat. Once hot, add the oil and then add the remaining 2 cloves of chopped garlic. Sauté for few minutes until it starts changing colour.
Then add the chopped onions.
Cook the onion for 2 to 3 minutes until soft and translucent.
Add in the prepared spinach puree and mix. Also, add around 1/2 cup water at the point.
Cover the pan and let it cook for 10 minutes on medium heat. The spinach will bubble a lot. Stir at regular intervals to avoid sticking at the bottom.

Once the spinach is cooked, add the garam masala, turmeric powder, red chilli powder and salt. Mix and cook for 1 minute.
Stir in the paneer and mix. Let the curry simmer for 3 to 4 minutes.
Switch off the flame, add lemon juice and kasuri methi and mix.