In a casserole, toast the rice with 20 gr of extra virgin olive oil. When the rice is hot throughout, add the boiling stock all at once and mix gently. Cover the casserole with the lid and allow to cook for 15 minutes on a low flame.
When the rice is cooked (depends on type of rice used) add the spinach, remove from the fire and add the grated parmesan cheese and butter. Mix thoroughly but gently until the cheese and butter melt and create a creamy risotto.
Allow to rest for 2 minutes in casserole with lid on and covered with a cloth.
Serve with grated parmesan and lemon slices.