Sauté the finely chopped onion in olive oil until translucent.

Add the washed rice and stir for a few minutes.

Add hot water, salt, and black pepper, then cook over low heat until the rice starts absorbing the liquid.

Sprinkle the roughly chopped spinach on top, lower the heat, and cook until the rice fully absorbs the liquid. Important: adding the spinach too early may release excess water and make the rice mushy.

Remove from heat, let rest for 10 minutes, then stir and serve.