1) Use a medium saucepan, to cook onion, garlic and bell pepper in butter over medium-high heat 3 to 5 minutes or until soft.
2) Fold in pumpkin, tomatoes, chicken broth, basil, salt and black pepper and stir properly.
3) Bring the mixture to a boil.
4) Reduce heat to low and cook gently over medium heat for 5 minutes.
5) In a bowl, place the pasta and top with the sauce before serving.