Preheat the oven to 180°C and warm a roasting tin inside.
Roast halved tomatoes drizzled with olive oil for 10 minutes.
Add thyme, balsamic vinegar, garlic, and seasoning then roast for 15 minutes.
Remove tomatoes and grease a large ovenproof dish with the reserved roasting oil.
Blend red peppers until smooth and mix with ricotta, pecorino, and spinach.
Fill pasta sheets with the pepper mixture and roll into cylinders.
Arrange cannelloni in the dish, top with tomatoes, and bake for 15 minutes at 180°C.
Garnish with shaved pecorino and serve with a dressed green salad.