Mashed potatoes are cheap and easy to make. They are great with sausages or roast chicken.
Peel four large floury potatoes (I like Agria) and cut into quarters. Half fill a medium pan with water and bring to a boil. Boil potatoes for approximately 15 minutes until tender. Drain cooked potatoes, then mash with a nob of butter. Add a little milk at a time and continue mashing potatoes until creamy.
Edited to add. At Wellington Road, we make a dairy-free version, with dairy-free margarine and rice milk. Still delicious!