Pasta, tin of tomatoes and spices - takes ten minutes. You can add things like bell pepper, mushrooms and meat, but it obviously takes longer.
Tuna salad - boil three eggs for ten minutes, mix mayonnaise and tuna in a bowl, chop up some pickles and add. After the eggs are hardboiled, chop those up and add them to the mix. Goes great on toast.
Beans on toast
I know that's only three, not five, but it's all I could think of so far.