6 cups of mashed potatoes
4 medium onions, segmented like an apple into 12 segments
12 oz slices button mushrooms (I prefer brown, aesthetically)
4 oz unsalted butter
8 - 10 oz Stilton
1 oz grated Parmagiano-Reggiano, Pecorino Romano or Grana Padano
Melt the 2 oz butter in a heavy skillet or saute pan over medium flame.
Add the mushrooms and saute until they have given up their liquid and start to brown.
When mushrooms are evenly brown, remove from the pan and set aside.
Lower the flame to medium-low - low and add the remaining butter.
Add onions and sweat until translucent.
Continue cooking, stirring occasionally until they begin to brown and become sticky; about 20 minutes.
Add the mushrooms back in to reheat them.
Preheat the oven to 400
Remove onions and mushrooms from flame and add salt an fresh ground pepper.
Butter a 2.8 Liter casserole dish. (Mine is Corningware Part F-2-B In French White from 1991 - Before the switch to stoneware - THANKS MOM!)
Spread half of the mashed potatoes over the bottom and up the sides of the casserole.
Spoon in the onion/mushroom mixture.
Crumble the Stilton over the top of the onion/mushroom mix.
Fill a pastry bag fitted with a large star tip with the remaining potatoes and pipe large stars over the top of the casserole. Alternatively you can simply spread the potatoes over the top, but piping is not just for decoration, It created more potato surface area so as the filling bubbles up between the "stars" it increases the flavor to the top crust.
Sprinkle the Parmagiano over the top and bake for about 20-25 minutes or until the top "crust" begins to turn golden brown and the Parmagiano has melted and browned.
If you used the piping bag, you will see bubbles coming up in between the Potatoes.
Pairs Well With
For all you cheese addicts our there, like myself, here is a delicious Cheese'centric take on shepherd's/cottage pie. Honestly it can be made with just about any cheese, I am lucky though, my Ovo-Lacto Vegetarian friend is as insane about blue cheese as I am. I choose Stilton, rather than Gorgonzola, Maytag or Saga because I think it stands up better to the amount of onion in the pie. Honestly, I have never tried it with Roqueforte. The measurement on the casserole dish is in Liters because I have old Corningware (the original PyroCeram stuff.) All the sizes are marked in liters instead of quarts. For anyone with the Pyrex standard sizes the dimensions of my casserole dish are 10 long 7 wide and 3 deep so a Pyrex 11 x 7 should work for this, but your pie will not be as thick because that dish is only 1 1/2 inches deep.
I wouldn't try it with Roquefort. First off, because it may be a little too strong in taste (though that's not a problem for me, but I know many people don't like strong cheeses). Secondly, because Roquefort (and I mean the real French Roquefort, here) contains a lot of water and somehow, when the pie is cooking, the mashed potatoes become runny. I have a shepherd's pie recipe that includes Roquefort in the mashed potatoes and I have yet to figure out how not to make the puree runny after incorporating the Roquefort...