Cut off the tops of the bell peppers, but keep them to use as lids. Wash the peppers well and remove the seeds.

Line a baking dish with parchment paper and place the peppers inside. Drizzle with a little olive oil. To help the peppers stand upright, crumple some parchment paper and place it inside each pepper. Bake at 400°F (200°C) for 10 minutes.

Cook the pasta and heat the meat sauce. Prepare the mozzarella and mortadella. Once everything is ready, toss the tagliatelle with a little sauce. Gradually fill each pepper, adding mozzarella and mortadella in the middle. Top with a bit more sauce and cover with the pepper tops. Bake for 25–30 minutes at 400°F (200°C).