In a pan over low-medium heat melt in 2 tsp butter. Add in your sausages and fry for 15-20mins, turning frequently. A lower heat will render down the fat and make the skin nice and crispy, whilst making sure the meat cooks properly.
Remove from pan and place to one side (or in the oven on low heat), leaving the fat behind. Add in your onion fry for another 10-15mins on the same heat, tossing every now and then. Season with salt and black pepper (good pinch of black pepper goes beautifully with sausages). Here lower heat will draw out the sugars and help the onions to caramelize, turning the golden and sweet. For truly caramelized onions see notes.
Slice down the centre of sausages and fold them open. Lightly butter one side of your bread, top with onions, place on your sausages, finish with a drizzle of ketchup/brown sauce then top with another slice of lightly buttered bread. Enjoy!
Quick Demo
Notes
a) Sausages - I recommend going for a neutral flavoured sausages, not added herbs or anything fancy. It gets a bit distracting. I also recommend investing in some good quality sausages - they are the star of the show after all!b) Caramelized Onions - To properly caramelize onions they need to be cooked for at least an hour on a really low heat. The will slow draw out the natural sugars in the onions and bring them to the surface. From there the sugar will begin to caramelize and turn the onions deep golden and sweet. If you want to do this I recommend doing it with a big batch and doing it in advance, or the sausage will go cold or dry out in the oven. c) Calories - based on using 4 tsp salted butter in total, no sauce.
* Percent Daily Values are based on a 2000 calorie diet.
*Nutrition is based on the absence of salt unless stated as a measurement in the ingredients. Cost is worked out based on ingredients bought from UK supermarkets, then divided by the number of servings. In both instances these values are just for guidance. Please check out my FAQ Page for more info.