Heat the pan in medium heat, add oil. Sauté the onion until translucent. Add spinach. Well season. Put aside and drain.

Heat the oven to 190 degree Celcius.

Mix the spinach mixture with ricotta cheese. Adjust seasoning.

Arrange the spinach mixture horizontally on a puff pastry. Roll it nicely tight.

Brush with egg-wash the surface of the puff pastry. Baked in the oven for 10 minutes or until golden brown.

Cut as desire before serve.