Cook pasta in a large saucepan of boiling, salted water according to packet instructions. Drain.
Meanwhile, preheat oven grill to high. Heat 1 tbs oil in a large flameproof baking dish over medium-high heat. Add onion and capsicum, then cook, stirring, for 5 minutes or until softened. Add mince and cook, breaking up any lumps with a wooden spoon, for 5 minutes or until browned.
Add seasoning to dish, then cook, stirring, for 1 minute or until well combined. Add pasta, salsa, beans and half the sour cream, then season and cook, stirring, until combined and warmed through. Remove pan from heat. Scatter top with cheese, then place under grill for 5 minutes or until golden.
Meanwhile, combine coriander, cucumber and remaining oil in a small bowl. Serve bake topped with cucumber salsa and remaining sour cream.