- Put water to boil. Submerge the tomatoes in the boiling water for a few seconds to loosen the skin. #Skin, and cut into small pieces getting rid of the seeds. Sprinkle oregano and salt on the tomatoes. #Heat up the oil, add the tomatoes. Simmer at very low heat until the tomatoes are very tender. Add a few tablespoons of water if necessary. Adjust salt. When the sauce is ready turn off the fire. Reserve.
- In a separate pan heat up the butter at low heat. Add the flour and stir vigorously until the two are well mixed. Add half the milk and stir until it reaches a uniform consistency. Add a pinch of salt and keep stirring until it becomes a thick cream. Reserve.
- Boil the spinach in the remaining milk adding a pinch of salt to it. As soon as the leaves are tender turn off the fire. Chop and mix with the Cheese.
- Fill the cannelloni with the Cheese. Lay on the tomato sauce and cover with the white sauce. Cover the baking pan and put in the oven until the cannelloni are tender.
- Uncover and bake until the sauce is thick.