Halve any large potatoes. Cook potatoes and fresh peas, if using, in a
large saucepan in boiling water for 10 minutes. Add frozen peas, if using.
Return mixture to boiling. Cover saucepan and cook vegetables 2 minutes
more or until potatoes are tender. Drain. Return potatoes and peas
to the saucepan.
Add margarine or butter, parsley and season to taste with salt and pepper.
Stir gently until butter melts.