To make the tomato sauce, preheat the oven to 150C/130C Fan/Gas 2.
Place the tomatoes in a roasting tin with the basil, garlic and oil, toss to coat well and slow roast for 2 hours. When roasted place in a blender and blitz until smooth. Season with salt and pepper.
To make the filling, bring a pan of water to the boil and blanch the rocket leaves for 30 seconds. Remove and refresh the rocket in cold water. Squeeze dry in a clean tea towel, then chop finely and place in a bowl. Add the ricotta, some grated nutmeg and the Parmesan. Season with salt and pepper and spoon into a piping bag.
To make the brown butter, heat the butter in a frying pan until it turns brown, remove from the heat and whisk in the lemon juice and a drizzle of oil. Set aside.
To assemble, turn the oven up to 200C/180C Fan/Gas 6, pipe some filling onto each pasta sheet and carefully roll up. Place tightly in a baking dish. Pour over the brown butter and bake for 20 minutes, until golden-brown.
To serve, spoon some tomato sauce onto each plate and top with the cannelloni, tear over some burrata and finish with some grated Parmesan and rocket.