Step by step

Cook the spinach for 2 minutes in boiling water and then strain well

Tips
If you like the idea of giving a little touch of something extra to your cannelloni, ‘stain’ the base of the oven dish and the surface of the pasta with fresh tomato sauce. If you’re not particularly bothered about keeping it strictly vegetarian, you could add some diced ham or mortadella to the filling.
Trivia
Outside Italy, this type of pasta is not always called "cannelloni". In Britain, for example, it is often cited in the singular, ‘cannellone’, because it is easier to pronounce than the plural. Elsewhere they refer to it as ‘manic he’ or ‘sleeves’.