Sausage pie is a kind of invention of mine.....
Get some saisages and cut them into half or thirds. Stick them in a casserole dish with a little oil and stick them in the oven for about 20 mins (until browned but not fully cooked)
WHile you are doing that you need to have potatoes boiling for mash (so I usually peel potatoes before putting the sausage in).
At the same time, another pan to fry a couple of onions and a couple of cloves of garlic.
Following?
Once onions are browned (around 5 mins ish, give them a good shake of mixed herbs, then put in a tinned of cheap tinned tomatoes and a tin of baked beans. Put in a really generous squirt of tomato puree too - probably a third to a half of a tube.
Let it mulsh down while the potatoes and sausages are doing.
When tatties are done, mash them. Once sausages are ready (not quite done....) add your tomato mixture and top with mash.
Stick in oven (around 200 degrees) and cook for 20-30 mins. I add grated cheese on top for last 5 mins.
We like it with sweet corn.