Preheat the oven to 400 degrees.
Place the first 3 ingredients in a saucepan, cover and bring to a boil. As soon as it boils, lower the heat to a simmer.
Steam the cauliflower for 6-8 minutes, or until fork tender.
Place the cauliflower mixture (you may not need to use all of the milk) and 1/3 cup cheese in a food processor and puree until smooth.
Slice the potatoes, preferably on a mandolin or by hand into very thin slices.
In a buttered 9×5 loaf pan, make a double layer of potatoes (this will use about 20 thin potato slices).
Cover with a tablespoon of the chopped sun-dried tomatoes.
Make another layer of potatoes.
Cover with a thick layer of cauliflower cream.
Make a layer of potatoes.
Cover with a tablespoon of sundried tomatoes.
Make another layer of potatoes.
Cover with a thick layer of cauliflower cream.
Spinkle the top with cheese and cover the loaf pan with tin foil.
Bake for 45 minutes. Uncover and continue to bake 10 more minutes until cheese becomes golden.
Throughly cool, cut into 15 rectangles and serve.