Fry the sausages for 10 minutes to brown the outsides. Remove and set aside. Next fry the onions for ten minutes until softened.
Return the sausages to the pan. Add the vegetables, tomatoes and butterbeans.
Bring to a simmer and leave to cook for 60 minutes, stirring occasionally.
Serve with either mashed potato or crusty bread. Top with chopped fresh coriander if you wish.
Notes
To note here, that the automated nutritional information is based on turkey sausages as low fat sausages are not in the nutrition database and turkey sausages were the closest fat content. My personal estimation is that using low fat sausages from a supermarket, such as those regularly sold by Tesco or Aldi, would result in a similar calorie count per portion - around 400 calories. The exact calorie and fat content will vary greatly according to the type of sausages used. Generally reduced fat pork varieties are available with fat content around 5-8%. Heck Chicken sausages are a good brand to look for but supermarkets' own label versions are good too. To make this low fat sausage casserole vegetarian, you can use Quorn sausages - these are also low fat.