1.   Cold milk and cold butter cause the starch in the potatoes to seize up, which is the main cause of glutinous mash potatoes.

2.   Cold butter in a hot pan may cook unevenly, parts of it burning before all the butter melts.

3.   Dice the cold butter and cut into the flour, using a pastry blender or a food processor.

4.   Just puree and heat the peppers, whisking in cold butter and any pan juices.

5.   Make a beurre manie, which is equal amounts of cold butter and flour lightly kneaded together.

6.   Reduce heat as low as possible, and begin whisking the cold butter, a piece at a time, into the pan.

7.   Remove from the oven and immediately stir in the remaining teaspoon of cold butter.

8.   Remove it from heat and beat it, adding cold butter bit by bit.

9.   Rub in the cold butter and shortening until mixture resembles coarse meal.

10.   Rub in cold butter until mixture resembles a coarse meal.