Put the pot onto the stove and warm. Add the olive oil, onion, garlic, carrot and pepper and sweat till softened.
Add the tomato sauce and the equal amount of water and leave to simmer.
Next, I like to use the food processor to get this smooth- and because it is quick. Put the squeezed spinach, ricotta, all but a large handful of the cheese and cream with a pinch of salt and a grind of pepper into the food processor and puree.
Spoon this mixture into the zip lock bag (or a piping bag). and cut a little whole in 1 corner. Use this to fill each cannelloni by filling 1 end and then turning around to fill the other. Don't fill them too full as it will squeeze out everywhere when it cooks.
Once all the tubes are full, taste the tomato sauce for salt and pepper and add if needed. Then lay the cannelloni's into the pot in a single layer and only overlap if necessary. The sauce should cover the cannelloni's. Sprinkle with the left over cheese and the breadcrumbs.
Cover with a lid or foil and bake for 20 minutes before removing the lid and baking a further 10 minutes.
Test that the pasta is cooked by breaking one of the tubes, before taking out of the oven.