Cook the pasta for 5 minutes in boiling water or until just tender. Drain and place in a large bowl. Mix in the sweetcorn, frozen peas, undiluted soup and 1 Tablespoon of the chives. Spoon half the pasta mixture into a large oven-proof dish. Spread half the tuna and tomatoes over the top. Cover with the remaining pasta mixture, tuna and tomatoes. Roll out the pastry on a lightly floured surface to a 25 cm square. Mix together the anchovies and puree and spread over the pastry to within 3 cm. Dampen the pastry edges, roll up like a swiss roll and cut into 16 rounds using a small sharp knife. Place on a baking sheet amd press down to flatten slightly. Preheat the oven to 180C/350F/Gas Mark 4. Scatter the grated cheddar cheese over the pasta mix and bake for 30 minutes. Increase the oven temperature to 200C/400F/Gas Mark 6 and place the spirals in the oven. Bake with the pasta for 15 minutes until spirals are golden brown and pasta bake is hot and bubbling. Arrange the spirals around the top of the pasta bake and scatter over the remaining chives. Serve at once.