Cook Perfetto Conchiglie pasta according to pack instructions.
Preheat the oven to 200 C.
In a sauce pan on medium heat, melt butter then add flour, salt, pepper and dry mustard and cook for 1 minute while stirring.
Add cooking cream and tomato sauce, mix well.
Continue cooking until thickness and smooth.
Reduce the heat and let simmer for 3 minutes.
Add cheese and stir well until it melts and sauce smooth again.
Fold in the cooked pasta and stuff the bell peppers with it and bake for 15 minutes.
Serve hot and enjoy!