Boil the pasta according to the instructions on the packet, then drain.
Meanwhile, heat the oil in a large frying pan, and add the pepper and mushrooms. Cook over a medium heat for 5 minutes, until fairly soft. Add the sweetcorn and black beans, along with the tin of tomatoes, spices, and plenty of salt and pepper. Bring to a simmer and cook for 5 more minutes. Remove the pan from the heat, and add the cream cheese. Stir until the cheese has melted into the sauce.
When the pasta is cooked, add it to the sauce, and mix well. Transfer to a suitably sized baking dish.
Sprinkle over about 2/3 of the grated cheese, and top with the slightly broken tortilla chips. Add the remaining cheese, and bake at 180°C (Gas Mark 4 / 350°F) for about 15 minutes, or until the tortilla chips are golden brown and crispy. Serve topped with fresh chopped coriander (cilantro), with guacamole and sour cream on the side.