Hungarian Christmas Mashed Potatoes - cooking recipe

Ingredients

1 tablespoon black mustard seeds
2 tablespoons butter
3 large onions (coarsely chopped)
2 tablespoons sweet Hungarian paprika
10 potatoes, peeled and quartered
1/2 cup butter (1 stick)
3/4 cup sour cream
1 egg
salt, to taste

Preparation

Boil peeled and quartered potatoes in salted water till tender.
While potatoes are cooking --.
Heat skillet. Add mustard seeds. Cover & shake until the popping slows. Add the butter & when melted, add the onions. Cover and cook over low heat for 15 minutes. Uncover, continue cooking over low heat for until very soft, dark & caramelized. Add the paprika. Stir over lowest heat for a minute or two until the paprika has lost its raw taste. Set aside.
Back to the potatoes --.
Strain off cooking water & mash. Add 1/2c of the sour cream and blend into potatoes. Add the egg into the potatoes and whip. Add the stick of butter & the remaining sour cream to taste. Stir in the onion mixture. Add salt to taste.