bring to a boil, then turn down to simmer for 1 hour, stirring occasionally. season to taste with salt and pepper.
peel the potatoes and chop them into approximately 1-inch pieces.
boil in salted water for 20-25 minutes, until very soft and starting to break down.
drain the potatoes, return them to the pot and beat with electric beaters. beat in the butter and cheese and season to taste with salt and pepper.
when the filling is ready, add the frozen peas and divide between three 8" x 4" tin foil disposable loaf pans (the ones with plastic lids). top with potato filling and smooth out the top with the back of a spoon.
cover 