1) Fill a large saucepan with water and bring to the boil. Add the pasta and cook for about 10 minutes or until al dente. Drain and reserve.
2) Preheat the oven to 180C/Gas 4. Butter a 3L casserole dish and set aside. Meanwhile, heat the olive oil in a large nonstick frying pan over a medium high heat. Add the onion, red pepper and jalapeno. Saute for 4 to 5 minutes or until tender.
3) Add the chicken, coriander, salt, cumin, pepper and tomatoes. Saute for 3 to 4 more minutes, then remove from the heat and set aside.
4) In a separate large pan over a medium heat, melt the butter. Remove from the heat and whisk in the flour, 1 teaspoon of salt and 1/4 teaspoon black pepper until smooth. Place the pan back on a medium-high heat, slowly whisk in the milk and bring to the boil while continuously whisking.
5) Reduce the heat and stir in the grated cheeses and the cream cheese until melted and smooth.
6) Stir in the pasta and chicken and then pour the mixture into the prepared casserole dish. In a medium bowl, combine the melted butter and breadcrumbs. Toss to coat and sprinkle the breadcrumbs and ground pumpkin seeds over the top of the pasta and cheese mix.
7) Bake for 20 to 25 minutes or until the cheese is bubbly and the topping is golden brown. Serve hot.