5 lbs. yellow-fleshed potatoes (such as Yukon gold)
½ cup sour cream
¼ cup butter
½ pkg. cream cheese or 150 grams Boursin cheese
salt and pepper to taste
(optional- roasted garlic, chives, chopped parsley, etc.)
Peel and boil potatoes in salted water until fork tender.
Drain, and allow to dry for a few minutes.
Add butter and allow it to melt.
Mash potatoes well, and add sour cream and cheese and flavourings as desired. Mixture should be light and creamy. If it seems dry, add more sour cream, a little at a time.
Taste and adjust seasoning. Mix vigorously to blend ingredients well.
Spread mixture in 9×13 serving dish (ovenproof)
Cover with foil, allow to cool and store in refrigerator for 1-2 days.
Before serving, remove from refrigerator a few hours before and allow to come to room temperature. Reheat at 375 degrees for about 45 minutes or until mixture is heated thoroughly. To test, insert paring knife in middle of casserole and feel the tip. If the tip is hot, the potatoes are ready. If a crispy top is desired, remove foil for the last 15 minutes, brush with a little melted butter and return to oven.